View Full CWNP CWNA-109 Exam Dumps and Practice Test Dumps

 

Question 1.

Which unit is commonly used to express RF power as an absolute value referenced to 1 milliwatt?

1. dBi
   2. dBd
   3. dBm
   4. dB

Correct Answer: 3. dBm

Explanation:

dBm expresses an absolute power level referenced to 1 milliwatt. A value of 0 dBm equals 1 mW, 10 dBm equals 10 mW, and 20 dBm equals 100 mW. This logarithmic representation is widely used in WLAN design and troubleshooting because RF power values can span a large range. dB represents a relative difference or gain rather than an absolute power level. dBi expresses antenna gain relative to an ideal isotropic radiator, while dBd references a half-wave dipole. Understanding the difference among these measurements is important when calculating transmit power, link budgets, antenna gain, cable loss, received signal strength, and regulatory power limits.

Question 2.

A wireless engineer increases transmit power from 10 mW to 100 mW. Approximately how much has the power increased in decibels?

1. 3 dB
   2. 10 dB
   3. 20 dB
   4. 100 dB

Correct Answer: 2. 10 dB

Explanation:

A tenfold increase in power corresponds to an increase of approximately 10 dB. Therefore, moving from 10 mW to 100 mW is a 10 dB increase. The commonly used Rule of 10s states that adding 10 dB multiplies power by ten, while subtracting 10 dB divides it by ten. The Rule of 3s states that adding about 3 dB approximately doubles power and subtracting about 3 dB approximately halves it. These mental shortcuts are valuable in wireless networking because they allow administrators to estimate transmit power, antenna gain, cable loss, and link-budget changes without repeatedly converting between logarithmic and linear measurements.

Question 3.

Which term describes the decrease in RF signal amplitude as the signal travels through space and encounters distance or obstacles?

1. Modulation
   2. Multiplexing
   3. Attenuation
   4. Amplification

Correct Answer: 3. Attenuation

Explanation:

Attenuation is the reduction in RF signal strength as electromagnetic energy propagates through free space or passes through physical materials. Distance causes free-space path loss, while walls, floors, furniture, people, and other objects can introduce additional attenuation. Different materials attenuate RF energy by different amounts, which is one reason predictive designs should be validated in the actual environment. Modulation is the process of encoding information onto a carrier signal, multiplexing combines multiple information streams or transmission resources, and amplification increases signal strength. Understanding attenuation is essential when determining access point placement, transmit power, antenna selection, coverage boundaries, and expected received signal levels.

Question 4.

Which phenomenon occurs when an RF wave changes direction because it passes from one medium into another medium with a different propagation velocity?

1. Reflection
   2. Diffraction
   3. Scattering
   4. Refraction

Correct Answer: 4. Refraction

Explanation:

Refraction occurs when an electromagnetic wave changes direction as it passes from one medium into another where its propagation speed differs. Although reflection, diffraction, scattering, and refraction may all affect WLAN signals, they describe different behaviors. Reflection occurs when a signal bounces from a surface. Diffraction describes a wave bending around an obstacle, while scattering occurs when a signal encounters an irregular surface or objects smaller than its wavelength and energy is redirected in multiple directions. Recognizing these propagation behaviors helps WLAN professionals understand multipath, unexpected coverage patterns, signal variation, and why actual RF behavior can differ substantially from simple line-of-sight assumptions.

Question 5.

Which RF propagation behavior occurs when a wireless signal encounters a large smooth surface and part of the energy bounces away from the surface?

1. Reflection
   2. Absorption
   3. Refraction
   4. Diffraction

Correct Answer: 1. Reflection

Explanation:

Reflection occurs when an RF signal encounters a surface large enough relative to the wavelength and some of the signal energy is redirected rather than passing through the material. Metal, concrete, glass, and other building materials can produce significant reflections depending on their properties and the angle of incidence. Reflections can create multiple copies of a signal arriving at a receiver at different times, a condition known as multipath. Modern 802.11 technologies can sometimes benefit from multipath, particularly with MIMO, but excessive reflections can also create complicated RF conditions. Absorption converts RF energy into other forms, diffraction bends energy around obstacles, and refraction changes direction between propagation media.

Question 6.

Which IEEE standard family defines wireless LAN operation commonly known as Wi-Fi?

1. IEEE 802.1
   2. IEEE 802.11
   3. IEEE 802.3
   4. IEEE 802.15

Correct Answer: 2. IEEE 802.11

Explanation:

IEEE 802.11 is the standards family that defines wireless local area networking technologies commonly associated with Wi-Fi. Different amendments and revisions define PHY capabilities, MAC behavior, management functions, security enhancements, quality-of-service features, and operation in different frequency bands. IEEE 802.3 defines Ethernet, IEEE 802.1 includes bridging and related LAN control standards, and IEEE 802.15 addresses wireless personal area networking technologies. CWNA candidates should understand both the technical purpose of major 802.11 amendments and how those amendments relate to real-world WLAN capabilities. Familiarity with standards helps administrators interpret client behavior, channel availability, data rates, security support, roaming capabilities, and compatibility requirements.

Question 7.

Which organization certifies interoperability of Wi-Fi products and owns the Wi-Fi CERTIFIED branding program?

1. FCC
   2. IEEE
   3. Wi-Fi Alliance
   4. IETF

Correct Answer: 3. Wi-Fi Alliance

Explanation:

The Wi-Fi Alliance is an industry organization that manages Wi-Fi certification programs intended to improve interoperability among wireless products implementing IEEE 802.11 technologies. IEEE develops the technical 802.11 standards, while regulatory agencies such as the FCC establish spectrum and transmission rules within their jurisdictions. The IETF develops many Internet-related standards and protocols but does not operate Wi-Fi product interoperability certification. Wi-Fi Alliance programs can cover security, generations of Wi-Fi technology, interoperability features, and other capabilities. WLAN professionals should distinguish standards development, regulatory authority, and industry certification because each organization plays a different role in how wireless technologies are created, legally operated, and marketed.

Question 8.

Which wireless LAN architecture consists of one access point and the stations associated with it?

1. ESS
   2. IBSS
   3. DS
   4. BSS

Correct Answer: 4. BSS

Explanation:

A Basic Service Set, or BSS, represents the fundamental infrastructure WLAN cell consisting of an access point and associated client stations. The AP provides the central coordination point for wireless communication within that BSS. An Extended Service Set, or ESS, consists of multiple BSSs connected through a distribution system and typically sharing an SSID to provide broader coverage and roaming. The distribution system, or DS, provides connectivity among access points and other network resources. An IBSS is associated with an older peer-to-peer ad hoc WLAN model without the normal infrastructure access point. Understanding these architectural terms is foundational for interpreting 802.11 frames, roaming, BSSIDs, and WLAN topology.

Question 9.

Which address typically identifies a specific Basic Service Set in an infrastructure WLAN?

1. BSSID
   2. SSID
   3. IP broadcast address
   4. Default gateway address

Correct Answer: 1. BSSID

Explanation:

The BSSID identifies a specific Basic Service Set. In a conventional infrastructure WLAN, it is commonly associated with the MAC address used by the access point radio for that BSS. The SSID is the human-readable network name that can be shared by multiple access points within an Extended Service Set. An IP broadcast address and default gateway operate at the network layer and do not uniquely identify an 802.11 BSS. Understanding BSSID versus SSID is important when troubleshooting roaming, interpreting protocol captures, analyzing neighboring access points, and distinguishing multiple radios or AP cells that advertise the same wireless network name.

Question 10.

Which 802.11 frame type is primarily used for functions such as association, authentication, beaconing, and probing?

1. Control frames
   2. Management frames
   3. Data frames
   4. Ethernet frames

Correct Answer: 2. Management frames

Explanation:

802.11 management frames support functions required to discover, establish, maintain, and terminate wireless relationships. Examples include Beacon, Probe Request, Probe Response, Authentication, Association Request, Association Response, Reassociation, Deauthentication, and Disassociation frames. Control frames perform functions such as acknowledgments and medium coordination, while data frames carry higher-layer user information. Ethernet frames are defined by IEEE 802.3 and are different from native 802.11 wireless frames. CWNA candidates should understand the purposes of major management and control frame subtypes because frame analysis is a fundamental technique for diagnosing connection failures, roaming problems, authentication issues, and other WLAN behavior.

Question 11.

Which CSMA mechanism is used by 802.11 stations to reduce the probability of transmitting at the same time as another station?

1. CSMA/CD
   2. Token passing
   3. CSMA/CA
   4. TDMA only

Correct Answer: 3. CSMA/CA

Explanation:

IEEE 802.11 WLANs use Carrier Sense Multiple Access with Collision Avoidance, or CSMA/CA. Wireless stations cannot reliably detect collisions while transmitting in the same way traditional shared Ethernet could, so they attempt to avoid collisions before transmitting. A station performs carrier sensing and follows contention procedures that can include interframe spaces and a random backoff timer. CSMA/CD is historically associated with shared half-duplex Ethernet. Token passing is used by other legacy networking technologies, while 802.11 is not based solely on fixed TDMA scheduling. Understanding contention is essential because every active station sharing a channel competes for airtime, affecting capacity, latency, and WLAN performance.

Question 12.

What happens to a station’s random backoff timer when the wireless medium becomes busy before the timer reaches zero?

1. It immediately transmits anyway
   2. It resets permanently to zero
   3. It disconnects from the access point
   4. It freezes the timer and resumes after the medium becomes available according to contention rules

Correct Answer: 4. It freezes the timer and resumes after the medium becomes available according to contention rules

Explanation:

During 802.11 contention, a station chooses a random backoff interval and counts it down while the medium remains available. If another transmission makes the medium busy before the counter reaches zero, the station freezes its remaining backoff value. After the medium is idle for the required interval, countdown can resume. This process reduces the likelihood that multiple stations transmit simultaneously. The station does not simply ignore the busy medium, permanently reset to zero, or disconnect from the access point. Understanding random backoff behavior helps explain why WLANs are shared-medium systems and why performance changes as the number of active contending devices increases.

Question 13.

Which 802.11 control frame is normally transmitted by a receiver after successfully receiving a unicast frame that requires confirmation?

1. ACK
   2. Beacon
   3. Probe Response
   4. Association Request

Correct Answer: 1. ACK

Explanation:

An acknowledgment, or ACK, is a control frame used to confirm successful reception of many unicast 802.11 frames. If the sender does not receive the expected ACK, it may assume the original transmission was unsuccessful and retransmit according to 802.11 retry procedures. Beacon, Probe Response, and Association Request are management frames rather than acknowledgment control frames. Because WLANs operate over an unreliable radio medium, positive acknowledgment and retransmission mechanisms are important for reliability. However, retries consume additional airtime, so high retry rates can significantly reduce capacity and often indicate interference, poor signal quality, contention, or other RF problems.

Question 14.

Which term describes unwanted RF energy that can degrade the ability of a Wi-Fi receiver to correctly interpret the desired signal?

1. Throughput
   2. Interference
   3. Modulation
   4. Beamforming

Correct Answer: 2. Interference

Explanation:

Interference is unwanted RF energy that makes it more difficult for a receiver to correctly decode the desired transmission. It can come from other Wi-Fi devices using overlapping or competing channels or from non-802.11 devices operating in or near the same spectrum. Interference may increase frame errors, retries, latency, and airtime utilization while reducing effective throughput. Throughput is the amount of useful data successfully delivered, modulation encodes information onto a carrier, and beamforming is a transmission technique intended to improve signal delivery. WLAN troubleshooting should consider both signal strength and interference because a strong desired signal does not guarantee good performance if the surrounding RF environment is noisy.

Question 15.

Which measurement compares the strength of the desired received signal with the surrounding noise level?

1. EIRP
   2. RSSI only
   3. Signal-to-noise ratio
   4. Antenna gain

Correct Answer: 3. Signal-to-noise ratio

Explanation:

Signal-to-noise ratio, or SNR, represents the difference between the strength of the desired signal and the background noise level. A higher SNR generally gives a receiver a better opportunity to distinguish the intended signal and successfully decode higher-rate modulation schemes. RSSI represents received signal strength but does not by itself describe how that signal compares with noise. EIRP describes effective transmitted power, while antenna gain describes directional concentration of RF energy. A client may show relatively strong received signal strength and still experience poor performance if the noise floor is also high, which is why SNR is such an important troubleshooting measurement.

Question 16.

Which antenna characteristic describes how strongly an antenna concentrates RF energy in particular directions compared with a reference antenna?

1. Frequency width
   2. Attenuation
   3. Polarization loss
   4. Gain

Correct Answer: 4. Gain

Explanation:

Antenna gain describes the degree to which an antenna concentrates RF energy in particular directions compared with a reference radiator. Gain does not create additional RF power; instead, it changes the radiation pattern by directing more energy toward some areas and less toward others. Gain is commonly expressed in dBi when referenced to an isotropic radiator. Higher-gain antennas often have narrower radiation patterns, which can be useful for directional links or specialized coverage requirements. Antenna selection should account for the desired coverage shape, mounting orientation, regulatory limits, client locations, and frequency bands rather than simply choosing the antenna with the highest gain value.

Question 17.

Which type of antenna is generally designed to radiate RF energy approximately equally in the horizontal plane around the antenna?

1. Omnidirectional antenna
   2. Highly directional parabolic antenna
   3. Yagi antenna
   4. Point-to-point dish antenna

Correct Answer: 1. Omnidirectional antenna

Explanation:

An omnidirectional antenna is designed to provide approximately 360-degree horizontal coverage around the antenna, although the three-dimensional radiation pattern is not truly spherical. Common indoor access point antennas are often omnidirectional because users may be located in many directions around the AP. Directional antennas such as Yagi or dish antennas concentrate more energy toward a particular direction and may be suitable for point-to-point links, corridors, warehouses, outdoor coverage, or other specialized environments. Antenna selection should be based on the intended coverage area and mounting design. Using the wrong antenna pattern can create excessive coverage in unwanted areas while leaving important areas underserved.

Question 18.

Which security technology introduced a substantially stronger standardized replacement for WEP and uses AES-based CCMP in its commonly deployed enterprise and personal implementations?

1. Open System authentication alone
   2. WPA2
   3. WEP
   4. MAC address filtering

Correct Answer: 2. WPA2

Explanation:

WPA2 significantly improved WLAN security compared with WEP and standardized the use of stronger AES-based CCMP protection for Wi-Fi networks. WEP has serious cryptographic weaknesses and should not be treated as adequate security. Open System authentication alone does not provide meaningful confidentiality, and MAC address filtering is easily bypassed because wireless addresses can be observed and impersonated. Enterprise WPA2 deployments can use 802.1X/EAP authentication with centralized identity services, while personal deployments commonly use a shared credential model. CWNA candidates should understand the evolution of WLAN security technologies, including why older mechanisms became unsuitable and how modern authentication and encryption approaches protect wireless communications.

Question 19.

Which WLAN security architecture commonly uses an authentication server and EAP to provide individual user or device authentication rather than one shared password?

1. 802.1X/EAP enterprise authentication
   2. Open authentication with no encryption
   3. Static WEP only
   4. MAC filtering only

Correct Answer: 1. 802.1X/EAP enterprise authentication

Explanation:

Enterprise WLAN security commonly uses IEEE 802.1X with an EAP method to authenticate individual users or devices through a centralized authentication infrastructure, frequently involving a RADIUS server. This model is more scalable and accountable than giving every user the same shared password because credentials can be individualized and centrally managed. Open networks provide no comparable authentication protection, WEP is obsolete and insecure, and MAC filtering is not strong authentication because addresses can be observed and spoofed. Understanding the roles of the supplicant, authenticator, and authentication server is important for designing, deploying, and troubleshooting enterprise Wi-Fi authentication.

Question 20.

During post-deployment WLAN validation, which approach provides the most useful evidence that actual coverage and performance meet the design requirements?

1. Assume the predictive model is always exact
   2. Check only access point LED status
   3. Review only the wired switch configuration
   4. Perform an on-site validation survey using appropriate measurements and test criteria**

Correct Answer: 4. Perform an on-site validation survey using appropriate measurements and test criteria

Explanation:

A post-deployment validation survey verifies how the WLAN actually performs in the installed environment. Predictive designs are valuable, but real buildings contain construction materials, furnishings, interference sources, client behaviors, and installation differences that can affect RF performance. Validation should evaluate measurements and requirements relevant to the design, which may include coverage, signal level, SNR, channel use, interference, roaming behavior, throughput, or application-specific performance. Access point LEDs and wired configuration checks are useful operational checks but cannot prove that wireless design requirements have been satisfied throughout the coverage area. On-site validation provides evidence that the deployed WLAN delivers the intended user experience.