Certified Wireless Network Professional (CWNA) Quiz

Reviewed by Editorial Team
The ProProfs editorial team is comprised of experienced subject matter experts. They've collectively created over 10,000 quizzes and lessons, serving over 100 million users. Our team includes in-house content moderators and subject matter experts, as well as a global network of rigorously trained contributors. All adhere to our comprehensive editorial guidelines, ensuring the delivery of high-quality content.
Learn about Our Editorial Process
| By Arifazizbutt
A
Arifazizbutt
Community Contributor
Quizzes Created: 1 | Total Attempts: 334
| Attempts: 334
SettingsSettings
Please wait...
  • 1/70 Questions

    AP-1 is a 3x3:2 AP. STA-3 is a 3x3:3 client. What is the maximum number of spatial streams thatcan be used for a downlink HT-OFDM transmission from AP-1 to STA-3?

    • One spatial stream, because the definition of the AP indicates that it is capable of only one spatial stream.
    • Three spatial streams, because the definition of the client indicates that it is capable of only three spatial streams.
    • Two spatial streams, because the definition of the AP indicates that it is capable of only two spatial streams
    • Three spatial streams, because the definition of the AP indicates that it is capable of only three spatial streams.
Please wait...
About This Quiz

This Certified Wireless Network Professional (CWNA) quiz assesses knowledge on WLAN RF transmission issues such as VSWR and return loss, RF signal behaviors like refraction and propagation, and calculations integral to network planning like Link Budget. It is crucial for professionals aiming to enhance their expertise in wireless networking.

Certified Wireless Network Professional (CWNA) Quiz - Quiz

Quiz Preview

  • 2. 

    What can cause an excessively high VSWR (Voltage Standing Wave Ratio) in a WLAN RFtransmission line?

    • Reflected direct current (DC) voltage on the main RF signal line

    • An impedance mismatch in the RF cables and connectors

    • Attenuation of the RF signal as it travels along the main signal path

    • Crosstalk (inductance) between adjacent RF conductors

    Correct Answer
    A. An impedance mismatch in the RF cables and connectors
    Explanation
    An impedance mismatch in the RF cables and connectors can cause an excessively high VSWR in a WLAN RF transmission line. When there is a mismatch between the impedance of the transmission line and the impedance of the connected devices, a portion of the RF signal is reflected back towards the source. This reflection can result in standing waves along the transmission line, leading to an increase in VSWR.

    Rate this question:

  • 3. 

    What phrase defines Equivalent Isotropically Radiated Power (EIRP)?

    • Reflected power due to an impedance mismatch in the signal path

    • The power output from the radio into the RF cable

    • The highest RF signal strength that is transmitted from a given antenna

    • Power supplied from the transmission line to the antenna input

    • The power output from the radio into the RF cable

    Correct Answer
    A. The highest RF signal strength that is transmitted from a given antenna
    Explanation
    The phrase "Equivalent Isotropically Radiated Power (EIRP)" refers to the highest RF signal strength that is transmitted from a given antenna.

    Rate this question:

  • 4. 

    ABC Company has just purchased a 6 dBi patch antenna. After performing some tests with the 6 dBi antenna, they have concluded that more antenna gain is needed to cover their outdoor courtyard. When choosing an antenna with higher gain, what other antenna characteristic will also always change?

    • Fresnel Zone size

    • Beamwidth

    • Maximum input power

    • Impedance

    • VSWR Ratio

    Correct Answer
    A. Beamwidth
    Explanation
    When choosing an antenna with higher gain, the beamwidth will also always change. Beamwidth refers to the angle of coverage of the antenna's main lobe. A higher gain antenna will have a narrower beamwidth, meaning it will focus its energy in a more concentrated direction. This can be beneficial in situations where a specific area needs to be targeted with a stronger signal. However, it also means that the antenna's coverage area will be reduced, as the signal will be less dispersed.

    Rate this question:

  • 5. 

    Prior to association, what parameter can 802.11 client devices measure and use to select theoptimal access point for association?

    • Signal strength of access point beacons received

    • Proximity to potential access points

    • Retry rate of probe request and response frames

    • Average round trip time to reach the Internet DNS server

    • Average round trip time to reach the IP router

    Correct Answer
    A. Signal strength of access point beacons received
    Explanation
    802.11 client devices can measure and use the signal strength of access point beacons received to select the optimal access point for association. This is because the signal strength indicates the quality of the wireless connection between the client device and the access point. By selecting the access point with the strongest signal, the client device can ensure a more stable and reliable connection.

    Rate this question:

  • 6. 

    An 802.11 WLAN transmitter that emits a 50 mW signal is connected to a cable with 3 dB of loss.The cable is connected to an antenna with 16 dBi of gain.What is the EIRP power output?

    • 1000 mW

    • 25 mW

    • 50 mW

    • 250 mW

    • 10 mW

    Correct Answer
    A. 1000 mW
    Explanation
    The EIRP (Effective Isotropic Radiated Power) is calculated by adding the transmitter power output (in this case, 50 mW) with the gain of the antenna (in this case, 16 dBi) and subtracting the loss of the cable (in this case, 3 dB). Converting the gain from dBi to dBd (decibels relative to a dipole), the calculation becomes: EIRP = Transmitter power output + Antenna gain - Cable loss = 50 mW + 16 dBd - 3 dB = 1000 mW. Therefore, the EIRP power output is 1000 mW.

    Rate this question:

  • 7. 

    When replacing the antenna of a WLAN device with a similar antenna type that has a higherpassive gain, what antenna characteristic will decrease?

    • Range

    • Beam width

    • Active gain

    • Receive sensitivity

    • Fresnel Zone size

    • Fresnel Zone size

    Correct Answer
    A. Beam width
    Explanation
    When replacing the antenna of a WLAN device with a similar antenna type that has a higher passive gain, the beam width will decrease. Beam width refers to the angle between the half-power points of the main lobe in the radiation pattern of the antenna. A higher passive gain means that the antenna focuses more of its energy in a narrower beam, resulting in a smaller beam width. This narrower beam width can lead to a more concentrated signal, but it may also reduce the coverage area or range of the WLAN device.

    Rate this question:

  • 8. 

    What statement about the IEEE 802.11e QoS facility is true?

    • 802.11 QoS is achieved by giving high priority queues a statistical advantage at winning contention.

    • Four 802.1p user priorities are mapped to eight 802.11 transmit queues.

    • When the Voice queue has frames awaiting transmission, no data will be transmitted from the Best Effort queue.

    • To improve efficiency, Block Acknowledgments are required for Voice and Video WMM queues

    • 802.11 control frames are assigned to the 802.11 EF priority queue.

    Correct Answer
    A. 802.11 QoS is achieved by giving high priority queues a statistical advantage at winning contention.
    Explanation
    The statement that is true about the IEEE 802.11e QoS facility is that 802.11 QoS is achieved by giving high priority queues a statistical advantage at winning contention. This means that the high priority queues have a higher chance of accessing the wireless medium and transmitting their data compared to lower priority queues. This ensures that important and time-sensitive data, such as voice or video, can be transmitted with minimal delay and higher reliability.

    Rate this question:

  • 9. 

    When using an RF splitter to connect one transceiver to sector antennas loss is incurred. What isthis loss called?

    • Conversion loss

    • Through loss

    • Active loss

    • Intentional loss

    Correct Answer
    A. Through loss
    Explanation
    Through loss refers to the loss of signal strength that occurs when using an RF splitter to connect one transceiver to sector antennas. This loss is a result of the signal being divided among multiple antennas, leading to a decrease in overall signal strength.

    Rate this question:

  • 10. 

    What term correctly completes the following sentence?802.11a/b/g used a mandatory 800ns guard interval. 802.11n introduced an optional short 400nsguard interval. Guard intervals (GI) are necessary in OFDM to reduce the likelihood of interferencebetween two consecutive ____________.

    • Frames

    • Packets

    • Segments

    • Bits

    • Bytes

    • Symbols

    Correct Answer
    A. Symbols
    Explanation
    The given question is asking about the term that correctly completes the sentence regarding guard intervals (GI) in OFDM. The sentence states that guard intervals are necessary in OFDM to reduce the likelihood of interference between two consecutive ________. Since OFDM divides a data stream into multiple subcarriers, the term that correctly completes the sentence is "Symbols." Guard intervals are used to separate symbols in OFDM to avoid interference between them.

    Rate this question:

  • 11. 

    A WLAN transmitter that emits a 200 mW signal is connected to a cable with 3 dB loss.If the cable is connected to an antenna with 10 dBi gain, what is the EIRP at the antenna element?

    • 10 dBm

    • 13 dBm

    • 20 dBm

    • 26 dBm

    • 30 dBm

    Correct Answer
    A. 30 dBm
    Explanation
    The EIRP (Effective Isotropic Radiated Power) is calculated by adding the transmitter power, cable loss, and antenna gain. In this case, the transmitter emits a 200 mW signal (23 dBm), the cable has a 3 dB loss, and the antenna has a 10 dBi gain. Adding these values together, we get 23 dBm - 3 dB + 10 dBi = 30 dBm. Therefore, the EIRP at the antenna element is 30 dBm.

    Rate this question:

  • 12. 

    What is always required to establish a high quality 2.4 GHz RF link at a distance of 3 miles(5 kilometers)?

    • Accurate Earth Bulge calculations

    • Minimum output power level of 2 W

    • Grid antennas at each endpoint

    • A Fresnel Zone that is at least 60% clear of obstructions

    • A minimum antenna gain of 11 dBi at both endpoints

    Correct Answer
    A. A Fresnel Zone that is at least 60% clear of obstructions
    Explanation
    To establish a high-quality 2.4 GHz RF link at a distance of 3 miles (5 kilometers), it is important to have a Fresnel Zone that is at least 60% clear of obstructions. The Fresnel Zone is an elliptical area around the direct line of sight between the transmitter and receiver. Obstructions within this zone can cause signal degradation and interference. By ensuring that at least 60% of the Fresnel Zone is clear, the RF signal can propagate with minimal interference, resulting in a high-quality link.

    Rate this question:

  • 13. 

    As a station moves away from the access point to which it is associated, it changes its data ratefrom 600 Mbps to 540 Mbps and then to 450 Mbps.What IEEE 802.11 term is used to describe this functionality?

    • Dynamic Rate Switching

    • Multirate Control

    • Modulation and Coding Selection

    • Rate Set Selectivity

    • Adaptive Rate Management

    Correct Answer
    A. Dynamic Rate Switching
    Explanation
    Dynamic Rate Switching is the correct term used to describe the functionality of a station changing its data rate as it moves away from the access point. This term refers to the ability of the station to automatically adjust its data rate based on the signal strength and quality of the wireless connection. By dynamically switching to lower data rates, the station can maintain a more reliable and stable connection even at longer distances from the access point. This functionality is an important feature in IEEE 802.11 wireless networks to optimize the performance and reliability of the wireless communication.

    Rate this question:

  • 14. 

    What word describes the bending of an RF signal as it passes through a medium of a varyingdensity from that of free space?

    • Reflection

    • Diffraction

    • Refraction

    • Diffusion

    • Scattering

    Correct Answer
    A. Refraction
    Explanation
    Refraction is the correct answer because it refers to the bending of an RF signal as it passes through a medium with a varying density from that of free space. When the signal encounters a change in the density of the medium, such as when it passes from air to water or from one type of material to another, it bends or changes direction. This phenomenon is known as refraction.

    Rate this question:

  • 15. 

    Return Loss is the decrease of forward energy in a system when some of the power is beingreflected back toward the transmitter.What will cause high return loss in an RF transmission system, including the radio, cables,connectors and antenna?

    • A Voltage Standing Wave Ratio (VSWR) of 1:1

    • Cross-polarization of the RF signal as it passes through the RF system

    • An impedance mismatch between components in the RF system

    • The use of cables longer than one meter in the RF system

    • High output power at the transmitter and use of a low-gain antenna

    Correct Answer
    A. An impedance mismatch between components in the RF system
    Explanation
    An impedance mismatch between components in the RF system can cause high return loss in an RF transmission system. When there is a mismatch in impedance between different components, such as the radio, cables, connectors, and antenna, some of the power from the forward energy gets reflected back towards the transmitter, resulting in a high return loss. This can lead to signal degradation and reduced efficiency in the transmission system.

    Rate this question:

  • 16. 

    XYZ Corporation is experiencing connectivity problems with their existing building-to-building bridge link. A concrete wall on the roof of one building is partially blocking the Fresnel Zone, and the connection is dropping many frames. The administrator moves the antenna to an area not obstructed by the concrete wall and then realizes the RF cable cannot reach the new location If an extension cable is added to move the antenna, what are the likely results?

    • The data throughput rate will increase because VSWR will decrease.

    • The Equivalent Isotropically Radiated Power (EIRP) will decrease.

    • The antenna’s azimuth beamwidth will decrease.

    • The size of the Fresnel zone will increase.

    • The likelihood of a direct lightning strike will increase.

    Correct Answer
    A. The Equivalent Isotropically Radiated Power (EIRP) will decrease.
    Explanation
    When the antenna is moved to a new location using an extension cable, the Equivalent Isotropically Radiated Power (EIRP) will decrease. EIRP is a measure of the power radiated by an antenna in a specific direction. By adding an extension cable, there will be additional cable losses, resulting in a decrease in the power radiated by the antenna. This decrease in EIRP can lead to a weaker signal and potentially lower data throughput rate.

    Rate this question:

  • 17. 

    Which of the following frequency ranges are specified for use by IEEE 802.11 radios? (Choose all that apply.)

    • 902 - 928 MHz

    • 2.4000 – 2.4835 GHz

    • 5.15 – 5.25 GHz

    • 5.470 – 5.725 GHz

    • 5.725 – 5.875 GHz

    Correct Answer(s)
    A. 2.4000 – 2.4835 GHz
    A. 5.15 – 5.25 GHz
    A. 5.470 – 5.725 GHz
    A. 5.725 – 5.875 GHz
    Explanation
    The specified frequency ranges for use by IEEE 802.11 radios are 2.4000 – 2.4835 GHz, 5.15 – 5.25 GHz, 5.470 – 5.725 GHz, and 5.725 – 5.875 GHz. These frequency ranges are within the commonly used 2.4 GHz and 5 GHz bands for Wi-Fi communication. The IEEE 802.11 standard defines these frequency ranges to ensure compatibility and avoid interference between different Wi-Fi devices operating in the same area.

    Rate this question:

  • 18. 

    What distinguishes an independent basic service set (IBSS) from an infrastructure basic serviceset (BSS)?

    • An IBSS does not have a distribution system (DS), but a BSS does.

    • An IBSS does not require beacon frames, but a BSS does.

    • An IBSS does not support 802.11 authentication or association, but a BSS does.

    • An IBSS does not support any 802.11ac enhancements, but a BSS does.

    Correct Answer
    A. An IBSS does not have a distribution system (DS), but a BSS does.
    Explanation
    The key difference between an independent basic service set (IBSS) and an infrastructure basic service set (BSS) is the presence of a distribution system (DS). An IBSS does not have a DS, which means that it operates in an ad-hoc mode where devices communicate directly with each other. On the other hand, a BSS has a DS, which is typically a wireless access point (AP) that acts as a central hub for devices to connect to. The DS in a BSS enables devices to communicate with each other and also provides connectivity to other networks, such as the internet.

    Rate this question:

  • 19. 

    In a long-distance RF link, what statement about Fade Margin is true?

    • The Fade Margin of a long-distance radio link should be equivalent to the receiver’s antenna gain.

    • A Fade Margin is unnecessary on a long-distance RF link if more than 80% of the first Fresnel zone is clear of obstructions

    • Fade Margin is an additional pad of signal strength designed into the RF system to compensate for unpredictable signal fading.

    • The Fade Margin is a measurement of signal loss through free space, and is a function of frequency and distance.

    Correct Answer
    A. Fade Margin is an additional pad of signal strength designed into the RF system to compensate for unpredictable signal fading.
    Explanation
    Fade Margin is an additional pad of signal strength that is intentionally added to the RF system. It is designed to compensate for unpredictable signal fading, which can occur due to various factors such as atmospheric conditions, interference, and obstacles in the signal path. By having a higher signal strength than what is actually required for reliable communication, the fade margin ensures that even if the signal weakens temporarily, it will still remain above the minimum threshold for successful transmission. This helps to maintain a reliable and stable long-distance RF link.

    Rate this question:

  • 20. 

    Which unit of measurement is an absolute unit that is used to quantify power levels on a linearscale?

    • DBm

    • W

    • dB

    • mW

    • VSWR

    Correct Answer
    A. DBm
    Explanation
    dBm is the correct answer because it is an absolute unit of measurement used to quantify power levels on a linear scale. It is a logarithmic unit that represents power relative to a reference level of 1 milliwatt (mW). dBm is commonly used in telecommunications and electronics to express power levels in a more convenient and manageable way.

    Rate this question:

  • 21. 

    What HT technology requires MIMO support on both the transmitter and receiver?

    • Spatial multiplexing

    • Short guard intervals

    • Maximal ratio combining

    • Orthogonal Frequency Division Multiplexing

    Correct Answer
    A. Spatial multiplexing
    Explanation
    Spatial multiplexing is a technology that requires MIMO (Multiple-Input Multiple-Output) support on both the transmitter and receiver. MIMO involves the use of multiple antennas to transmit and receive multiple data streams simultaneously. Spatial multiplexing takes advantage of the multiple antennas to transmit different parts of the data simultaneously, increasing the overall data rate. Therefore, in order to utilize spatial multiplexing, both the transmitter and receiver must support MIMO technology.

    Rate this question:

  • 22. 

    Which antenna types are commonly used by indoor Wi-Fi devices in a MIMO diversityimplementation? (Choose 2)

    • Grid

    • Dipole

    • Patch

    • Dish

    • Sector

    Correct Answer(s)
    A. Dipole
    A. Patch
    Explanation
    Dipole and Patch antennas are commonly used by indoor Wi-Fi devices in a MIMO diversity implementation. Dipole antennas are simple and omnidirectional, meaning they radiate signals in all directions. Patch antennas, on the other hand, are directional and provide a focused signal in a specific direction. Using a combination of these two antenna types allows for improved signal coverage and diversity, which helps to enhance the overall performance and reliability of the Wi-Fi network in indoor environments.

    Rate this question:

  • 23. 

    What are two channel modes specified by the 802.11n (High Throughput) PHY? (Choose 2) 

    • 20 MHz

    • 20/40 MHz

    • 40/80 MHz

    • 22 MHz

    • 80 MHz

    • 160 MHz

    Correct Answer(s)
    A. 20 MHz
    A. 20/40 MHz
    Explanation
    The 802.11n (High Throughput) PHY specifies two channel modes: 20 MHz and 20/40 MHz. These channel modes determine the available bandwidth for wireless communication. The 20 MHz channel mode provides a single 20 MHz wide channel for data transmission. The 20/40 MHz channel mode allows for the aggregation of two 20 MHz channels to provide a wider bandwidth of 40 MHz, which can increase the data throughput.

    Rate this question:

  • 24. 

    A Wi-Fi Alliance interoperability certificate indicates that a device is a/b/g/n certified. It furtherindicates one transmit and receive spatial stream for both the 2.4 GHz and 5.0 GHz bands. Itfurther indicates support for both WPA and WPA2 Enterprise and Personal. Finally, it indicatessupport for EAP-TLS, EAP-TTLS/MSCHAPv2, PEAPv0/EAP-MSCHAPv2 and PEAPv1/EAP-GTC.Which one of the following statements is false?

    • This client device supports protection mechanisms such as RTS/CTS and/or CTS-to-Self.

    • This client device supports both TKIP and CCMP cipher suites.

    • 300 Mbps is the maximum supported data rate for this device.

    • This client device supports the ERP, OFDM, and HT physical layer specifications.

    • This client device supports X.509 certificates for EAP authentication

    Correct Answer
    A. 300 Mbps is the maximum supported data rate for this device.
    Explanation
    The given statement is false because the question states that the device is certified as a/b/g/n, which means it supports up to 600 Mbps data rate for 2.4 GHz band and up to 1300 Mbps data rate for 5.0 GHz band. Therefore, the maximum supported data rate for this device is not 300 Mbps.

    Rate this question:

  • 25. 

    In an enterprise WLAN, what condition will prevent a dual-band VHT/HT client device fromperforming a fast and seamless transition (i.e. latency-sensitive applications are not disrupted)between two access points that are managed by the same WLAN controller?

    • The current AP is using channel 1 and the new AP is using channel 40.

    • The SSID of the current AP does not match the SSID of the new AP.

    • The current AP supports only HT and the new AP is VHT capable.

    • The access points are hiding the SSID in Beacons and Probe Response frames

    Correct Answer
    A. The SSID of the current AP does not match the SSID of the new AP.
    Explanation
    If the SSID of the current AP does not match the SSID of the new AP, it will prevent a dual-band VHT/HT client device from performing a fast and seamless transition between the two access points. This is because the client device needs to authenticate and associate with the new AP, and if the SSID does not match, the client device will not be able to connect to the new AP. As a result, latency-sensitive applications may be disrupted during the transition.

    Rate this question:

  • 26. 

    What term describes the effect of increasing the intensity of an RF wave with an antenna byfocusing the energy in a specific direction? 

    • Beam Compression

    • Distributed Radiation

    • Active Amplification

    • Passive Gain

    • RF Flooding

    Correct Answer
    A. Passive Gain
    Explanation
    Passive Gain describes the effect of increasing the intensity of an RF wave with an antenna by focusing the energy in a specific direction. This term refers to the process of using passive elements such as reflectors or directors to shape the radiation pattern of the antenna, resulting in increased signal strength in the desired direction.

    Rate this question:

  • 27. 

    Which data rate is supported by 802.11g radios that is not supported by 802.11a radios?

    • 9 Mbps

    • 11 Mbps

    • 12 Mbps

    • 54 Mbps

    • 65 Mbps

    • 130 Mbps

    Correct Answer
    A. 11 Mbps
    Explanation
    802.11g radios support a data rate of 11 Mbps, which is not supported by 802.11a radios. The 802.11a standard supports data rates of 6, 9, 12, 18, 24, 36, 48, and 54 Mbps, while the 802.11g standard supports data rates of 1, 2, 5.5, 6, 9, 11, 12, 18, 24, 36, 48, and 54 Mbps. Therefore, the correct answer is 11 Mbps.

    Rate this question:

  • 28. 

    What is the intended use for the WLAN hardware known as a pole or mast mount unit?

    • Mounting a lightning arrestor to a grounding rod

    • Mounting an omnidirectional antenna to a mast

    • Mounting an RF amplifier to a dipole antenna

    • Mounting a PoE injector to a perforated radome

    • Mounting an access point to a site survey tripod

    Correct Answer
    A. Mounting an omnidirectional antenna to a mast
    Explanation
    The WLAN hardware known as a pole or mast mount unit is intended to be used for mounting an omnidirectional antenna to a mast. This type of hardware allows for secure installation of the antenna on top of a mast or pole, providing optimal coverage and signal distribution in all directions.

    Rate this question:

  • 29. 

    The center frequency of channel 1 in the 2.4 GHz band is 2.412 GHz (2412 MHz).What is the center frequency of channel 4?

    • 2.413 GHz

    • 2.417 GHz

    • 2.422 GHz

    • 2.427 GHz

    • 2.437 GHz

    Correct Answer
    A. 2.427 GHz
    Explanation
    The center frequency of channel 4 can be determined by adding 5 to the center frequency of channel 1. Since the center frequency of channel 1 is 2.412 GHz, adding 5 to it gives us 2.417 GHz. Therefore, the center frequency of channel 4 is 2.417 GHz.

    Rate this question:

  • 30. 

    What statements about the SSID are true? (Choose 2)

    • The SSID is a security session identifier used in RSNs.

    • The SSID must be included in an association request frame.

    • The SSID is an alphanumeric value assigned to device manufacturers by the IEEE.

    • The SSID is a pseudo-random number assigned to each client by an AP.

    • The SSID is an alphanumeric value with a maximum length of 32 octets.

    • When configuring a new network, creating an SSID is optional.

    Correct Answer(s)
    A. The SSID must be included in an association request frame.
    A. The SSID is an alphanumeric value with a maximum length of 32 octets.
    Explanation
    The SSID must be included in an association request frame because it is used to identify the network that the client wants to connect to. The SSID is an alphanumeric value with a maximum length of 32 octets, which means it can consist of both letters and numbers and cannot exceed 32 characters in length. This is the standard limit set by the IEEE for SSID values.

    Rate this question:

  • 31. 

    What statements about the beamwidth of an RF antenna are true? (Choose 2)

    • The lower the gain of an antenna, the more narrow one or both beamwidths become

    • The beamwidth patterns on an antenna polar chart indicate the point at which the RF signal stops propagating

    • Horizontal and vertical beamwidth are calculated at the points in which the main lobe decreases power by 3 dB.

    • Horizontal beamwidth is displayed (in degrees) on the antenna’s Azimuth Chart.

    Correct Answer(s)
    A. Horizontal and vertical beamwidth are calculated at the points in which the main lobe decreases power by 3 dB.
    A. Horizontal beamwidth is displayed (in degrees) on the antenna’s Azimuth Chart.
    Explanation
    The first statement is true because the gain of an antenna is inversely proportional to the beamwidth. A lower gain antenna will have a narrower beamwidth.

    The second statement is also true because the beamwidth patterns on an antenna polar chart indicate the boundaries at which the RF signal stops propagating. These patterns show the extent of the antenna's coverage area.

    Therefore, the correct answer is that horizontal and vertical beamwidth are calculated at the points in which the main lobe decreases power by 3 dB, and horizontal beamwidth is displayed (in degrees) on the antenna's Azimuth Chart.

    Rate this question:

  • 32. 

    What factors will have the most significant impact on the amount of wireless bandwidth availableto each station within a BSS? (Choose 2)

    • The number of client stations associated to the BSS

    • The power management settings in the access point’s beacons

    • The presence of co-located (10m away) access points on non-overlapping channels

    • The data rates at which nearby client stations are transmitting and receiving data

    • The layer 3 protocol used by each station to transmit data over the wireless link

    Correct Answer(s)
    A. The number of client stations associated to the BSS
    A. The data rates at which nearby client stations are transmitting and receiving data
    Explanation
    The number of client stations associated to the BSS will have a significant impact on the amount of wireless bandwidth available to each station because as the number of client stations increases, the available bandwidth needs to be divided among more devices, resulting in reduced bandwidth per station.

    The data rates at which nearby client stations are transmitting and receiving data will also have a significant impact on the available wireless bandwidth. If nearby client stations are transmitting and receiving data at high data rates, it can consume a significant portion of the available bandwidth, leaving less bandwidth for other stations in the BSS.

    Rate this question:

  • 33. 

    What answers correctly complete the following sentence?____________ and ____________ carrier sense functions are used to determine if the wirelessmedium is busy. (Choose 2)

    • Backoff

    • Pseudo-random

    • Virtual

    • Active

    • Physical

    • Interframe

    • Vector

    Correct Answer(s)
    A. Virtual
    A. Physical
    Explanation
    Virtual and Physical carrier sense functions are used to determine if the wireless medium is busy. Virtual carrier sense involves monitoring the wireless channel for any ongoing transmissions from other devices, while physical carrier sense involves detecting the presence of any energy or signals on the wireless medium. Both functions are necessary to ensure that a device can accurately determine if the medium is busy before transmitting data.

    Rate this question:

  • 34. 

    As XYZ Company’s wireless specialist, you have been asked to troubleshoot some unexpectedframe patterns in a wireless protocol capture. Your peers explain that the network’s beacon framesare inconsistent. That is, the BSSID is the same for all beacons, but the source address variesbetween three different addresses.What network configuration would cause this beacon frame behavior?

    • A single AP supports multiple BSSs with different SSIDs

    • A virtual cell single channel network has been implemented

    • The beacons are from an IBSS instead of a BSS

    • Three APs still share the same default configuration.

    Correct Answer
    A. The beacons are from an IBSS instead of a BSS
    Explanation
    The beacons are from an IBSS instead of a BSS. In an Independent Basic Service Set (IBSS), also known as an ad hoc network, the devices communicate directly with each other without the need for an access point (AP). In this case, the BSSID (Basic Service Set Identifier) remains the same for all beacons, but the source address varies between three different addresses because each device in the ad hoc network takes turns broadcasting the beacons. This is different from a Basic Service Set (BSS) where the beacons would typically have the same BSSID and source address.

    Rate this question:

  • 35. 

    What feature(s) are most likely to be supported by 802.11 enterprise-class WLAN controllers?(Choose 4)

    • Link aggregation / port trunking

    • 802.1p and DSCP QoS

    • BGP and Frame Relay

    • Captive web portals

    • IGMP snooping

    Correct Answer(s)
    A. Link aggregation / port trunking
    A. 802.1p and DSCP QoS
    A. Captive web portals
    A. IGMP snooping
    Explanation
    802.11 enterprise-class WLAN controllers are designed to support various features that are essential for enterprise networks. Link aggregation / port trunking is a feature that allows multiple physical links to be combined into a single logical link, increasing bandwidth and providing redundancy. 802.1p and DSCP QoS are Quality of Service mechanisms that prioritize and manage network traffic, ensuring that critical data receives higher priority and better performance. Captive web portals are used for guest authentication and access control, allowing organizations to provide secure Wi-Fi access to visitors. IGMP snooping is a feature that monitors and manages multicast traffic, optimizing network performance by forwarding multicast packets only to the devices that have subscribed to them.

    Rate this question:

  • 36. 

    What factors influence the distance that an RF signal can be effectively received? (Choose 3)

    • MAC layer encryption

    • Transmitting station’s power source

    • Free Space Path Loss

    • Transmitting station’s output power

    • Temperature in the Fresnel zone

    • Receiving station’s radio sensitivity

    Correct Answer(s)
    A. Free Space Path Loss
    A. Transmitting station’s output power
    A. Receiving station’s radio sensitivity
    Explanation
    The three factors that influence the distance that an RF signal can be effectively received are Free Space Path Loss, Transmitting station’s output power, and Receiving station’s radio sensitivity. Free Space Path Loss refers to the loss of power as the signal travels through space. The Transmitting station’s output power determines the strength of the signal being transmitted. The Receiving station’s radio sensitivity indicates how well the station can detect and interpret the incoming signal. These factors collectively determine the effective range of an RF signal.

    Rate this question:

  • 37. 

    As an RF wave propagates through space, the wave front experiences natural expansion thatreduces its signal strength in an area. What term describes the rate at which this expansionhappens?

    • MU-MIMO

    • Inverse square law

    • Path spread phenomenon

    • Fresnel zone thinning

    • Ohm’s law

    Correct Answer
    A. Inverse square law
    Explanation
    The term that describes the rate at which the expansion of the wave front happens is the inverse square law. According to this law, the intensity of the wave decreases as the square of the distance from the source increases. This means that as the RF wave propagates through space, the signal strength diminishes rapidly with distance.

    Rate this question:

  • 38. 

    When compared with legacy Power Save mode, how does VHT TXOP power save improvebattery life for devices on a WLAN?

    • VHT TXOP power save allows stations to enter sleep mode and legacy Power Save does not.

    • VHT TXOP power save uses the partial AID in the preamble to allow clients to identify frames targeted for them.

    • Legacy Power Save mode was removed in the 802.11ac amendment.

    • VHT TXOP power save allows the WLAN transceiver to disable more components when in a low power state.

    Correct Answer
    A. VHT TXOP power save uses the partial AID in the preamble to allow clients to identify frames targeted for them.
    Explanation
    VHT TXOP power save improves battery life for devices on a WLAN by using the partial AID in the preamble to allow clients to identify frames targeted for them. This means that devices can selectively wake up from sleep mode only when there are frames specifically meant for them, reducing the amount of time spent in active mode and conserving battery power.

    Rate this question:

  • 39. 

    What statement is true concerning the use of Orthogonal Frequency Division Multiplexing (OFDM)in IEEE 802.11 WLANs?

    • 802.11a and 11n use six (6) “pilot” subcarriers as a reference for the receiver to detect frequency and phase shifts of the signal.

    • 802.11a/g/n OFDM includes several combinations of modulation and coding to achieve data rates from 1-600 Mbps.

    • With 802.11a OFDM, 16-QAM provides either 48 or 54 Mbps data rates, depending upon coding rates.

    • 802.11ac VHT-OFDM utilizes 256-QAM, which increases the data rate significantly over 64- QAM available in HT-OFDM.

    • In 802.11a OFDM, fifty-six (56) subcarriers are used as parallel symbol transmission paths to carry data.

    Correct Answer
    A. 802.11ac VHT-OFDM utilizes 256-QAM, which increases the data rate significantly over 64- QAM available in HT-OFDM.
    Explanation
    802.11ac VHT-OFDM utilizes 256-QAM, which increases the data rate significantly over 64-QAM available in HT-OFDM. This means that 802.11ac VHT-OFDM can transmit more data per symbol, resulting in higher data rates compared to HT-OFDM. By using a higher order modulation scheme, more bits can be encoded into each symbol, allowing for faster transmission speeds. This improvement in data rate is a key advantage of 802.11ac VHT-OFDM over previous OFDM technologies.

    Rate this question:

  • 40. 

    The OSI model is a 7-layer model for understanding the functions of a communication system.What OSI sublayers are specifically addressed by the IEEE 802.11-2012 standard? (Choose 2)

    • Network

    • PPDU

    • PLCP

    • MAC

    • IP

    • Transport

    Correct Answer(s)
    A. PLCP
    A. MAC
    Explanation
    The IEEE 802.11-2012 standard specifically addresses the Physical Layer Convergence Procedure (PLCP) and Media Access Control (MAC) sublayers of the OSI model. These two sublayers are crucial in the functioning of a communication system as they handle the physical transmission of data and the access control to the medium, respectively. The PLCP sublayer is responsible for converting data into a format suitable for transmission, while the MAC sublayer manages the access to the shared communication medium.

    Rate this question:

  • 41. 

    Which answer correctly completes the following sentence?The WMM certification, created by the Wi-Fi Alliance, is based on the ___________ coordinationfunction with support for ___________ QoS priority.

    • Hybrid, contention-based

    • Point, scheduled

    • Dynamic, distributed

    • Distributed, trigger-and-delivery

    • Enhanced, contention-free

    Correct Answer
    A. Hybrid, contention-based
    Explanation
    The WMM certification, created by the Wi-Fi Alliance, is based on the hybrid coordination function with support for contention-based QoS priority. This means that the WMM certification utilizes a combination of both contention-based and scheduled access methods to prioritize quality of service. Contention-based access allows devices to compete for access to the network, while the hybrid coordination function ensures that QoS priorities are maintained.

    Rate this question:

  • 42. 

    You are implementing a VHT-capable AP. Which one of the following channels is available in the 802.11ac amendment to the 802.11-2012 standard, which was not available in the standard beforethis amendment?

    • 153

    • 144

    • 161

    • 56

    • 48

    Correct Answer
    A. 144
    Explanation
    In the 802.11ac amendment to the 802.11-2012 standard, the channel 144 became available, which was not available in the standard before this amendment.

    Rate this question:

  • 43. 

    When a client station sends a broadcast probe request frame with a wildcard SSID, how do APsrespond?

    • After waiting a SIFS, all APs reply at the same time with a probe response.

    • After waiting a SIFS, a designated AP sends an ACK, and then replies with a probe response.

    • Each AP checks with the DHCP server to see if it can respond and then acts accordingly.

    • For each probe request frame, only one AP may reply with a probe response.

    • Each AP responds in turn after preparing a probe response and winning contention.

    Correct Answer
    A. Each AP responds in turn after preparing a probe response and winning contention.
    Explanation
    When a client station sends a broadcast probe request frame with a wildcard SSID, all APs compete for the opportunity to respond. After waiting a SIFS (Short Interframe Space), each AP prepares a probe response and participates in contention to determine which AP will respond first. The AP that wins contention sends its probe response, and then other APs respond in a sequential manner, taking turns after preparing their own probe responses. This ensures that multiple APs do not reply simultaneously, preventing potential collisions and ensuring a more efficient communication process.

    Rate this question:

  • 44. 

    What component of the 802.11 standard allows stations to reserve access to the RF medium for aspecified period of time?

    • Short guard intervals

    • DTIM Interval

    • Listen Interval

    • Probe Request frames

    • RTS or CTS frames

    Correct Answer
    A. RTS or CTS frames
    Explanation
    RTS (Request to Send) and CTS (Clear to Send) frames are components of the 802.11 standard that allow stations to reserve access to the RF (Radio Frequency) medium for a specified period of time. When a station wants to transmit data, it sends an RTS frame to the intended recipient, requesting permission to transmit. The recipient responds with a CTS frame, granting permission and reserving the medium for the sender. This mechanism helps prevent collisions and ensures that only one station transmits at a time, improving the overall efficiency and reliability of the wireless network.

    Rate this question:

  • 45. 

    In an 802.11n WLAN with a heterogeneous set of associated client devices including 802.11b,11g, and 11n, what HT protection mode will the BSS use?

    • Mode 0: No protection mode (Greenfield)

    • Mode 1: Nonmember protection mode

    • Mode 2: 20 MHz protection mode

    • Mode 3: Non-HT mixed mode

    Correct Answer
    A. Mode 3: Non-HT mixed mode
    Explanation
    In an 802.11n WLAN with a heterogeneous set of associated client devices including 802.11b, 11g, and 11n, the BSS will use Mode 3: Non-HT mixed mode. This mode is used to protect the non-HT (802.11b/g) devices from interference caused by the HT (802.11n) devices. It allows the BSS to operate in mixed mode, supporting both HT and non-HT devices simultaneously. This ensures compatibility and optimal performance for all devices in the network.

    Rate this question:

  • 46. 

    What factors are taken into account when calculating the Link Budget of a point-to-point outdoorWLAN bridge link?

    • Antenna height

    • Transmit antenna gain

    • Transmit power

    • Operating frequency

    Correct Answer(s)
    A. Transmit antenna gain
    A. Transmit power
    A. Operating frequency
    Explanation
    The factors that are taken into account when calculating the Link Budget of a point-to-point outdoor WLAN bridge link are the transmit antenna gain, transmit power, and operating frequency. The transmit antenna gain refers to the ability of the antenna to focus the transmitted signal in a specific direction, which can affect the signal strength and coverage. The transmit power is the amount of power that is being transmitted, which also affects the signal strength. The operating frequency is the frequency at which the wireless communication is taking place, and different frequencies can have different propagation characteristics and signal losses.

    Rate this question:

  • 47. 

    The IEEE 802.11a/n/ac physical layer technologies utilize the 5 GHz frequency band. What is trueof the channels in this frequency spectrum?

    • 14 channels are available worldwide

    • 11 channels are available worldwide.

    • Regulatory domains worldwide require DFS and TPC in all these channels.

    • DFS may be required in some regulatory domains on some channels.

    • 802.11 channels are separated by 5 Mhz

    Correct Answer
    A. DFS may be required in some regulatory domains on some channels.
    Explanation
    DFS (Dynamic Frequency Selection) may be required in some regulatory domains on some channels. The 5 GHz frequency band used by IEEE 802.11a/n/ac has a limited number of available channels. In order to avoid interference with radar systems, certain channels require DFS, which is a mechanism that allows devices to detect and avoid radar signals. However, not all regulatory domains require DFS on all channels, so it may only be required in certain regions on specific channels.

    Rate this question:

  • 48. 

    In an 802.11 2.4 GHz system, what 22 MHz channels are considered non-overlapping? (Choose2)

    • Channels 5 and 10

    • Channels 1 and 5

    • Channels 3 and 7

    • Channels 2 and 8

    • Channels 8 and 11

    • Channels 10 and 13

    Correct Answer(s)
    A. Channels 5 and 10
    A. Channels 2 and 8
  • 49. 

    What term correctly completes the following sentence?In an IEEE 802.11 frame, the IP packet is considered by the MAC layer to be a(n) _________.

    • MAC Service Data Unit (MSDU)

    • MAC Protocol Data Unit (MPDU)

    • IP datagram

    • PLCP Service Data Unit (PSDU)

    • PLCP Protocol Data Unit (PPDU)

    Correct Answer
    A. MAC Service Data Unit (MSDU)
    Explanation
    In an IEEE 802.11 frame, the IP packet is considered by the MAC layer to be a(n) MAC Service Data Unit (MSDU). The MSDU is the data unit that is passed from the higher layers (such as the IP layer) to the MAC layer for transmission over the wireless network. It contains the payload data and any necessary headers or trailers added by the higher layers. The MAC layer then encapsulates the MSDU into a MAC Protocol Data Unit (MPDU) for transmission over the wireless medium. Therefore, the correct term to complete the sentence is MAC Service Data Unit (MSDU).

    Rate this question:

Quiz Review Timeline (Updated): Oct 8, 2024 +

Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

  • Current Version
  • Oct 08, 2024
    Quiz Edited by
    ProProfs Editorial Team
  • Jun 23, 2016
    Quiz Created by
    Arifazizbutt

Recent Quizzes

CWNA Wireless Network Administrator CWNA Wireless Network Administrator
Computer Knowledge - Quiz -3 Computer Knowledge - Quiz -3
Take The Trivia Questions Quiz on Radio Resource Management! Take The Trivia Questions Quiz on Radio Resource Management!
Advertisement