CWNP CWNP Certifications CWNA-108 Questions & Answers

• Question 81:

  The BSA of an AP covers the area used by the sales and marketing department. Thirty-five stations operate in this space. The users indicate that they need more throughput and all stations are 5 GHz capable 802.11ac clients. The current AP configuration uses 20 MHz channels in both 2.4 GHz and 5 GHz. What is the least expensive solution available for increasing throughput for these users without implementing configuration options that are not recommended?

  A. Use a 160 MHz channel on the 5 GHz radio

  B. Use a 40 MHz channel on the 5 GHz radio

  C. Install a second AP in the coverage area

  D. Use a 40 MHz channel on the 2.4 GHz radio

  Correct Answer: C

• Question 82:

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

  A. Inverse square law

  B. Ohm's law

  C. Fresnel zone thinning

  D. MU-MIMO

  Correct Answer: A

• Question 83:

  What statement about 802.11 WLAN performance is true?

  A. In modern networks, both centralized and distributed data forwarding work well for most standard office deployments

  B. In most WLANs, no special skill or tuning is required to get peak performance

  C. WLANs perform better as more wireless clients connect with each AP

  D. To get the best performance out of an AP, you should disable data rates of 72 Mbps and lower

  Correct Answer: D

• Question 84:

  What statement about the beamwidth of an RF antenna is true?

  A. Horizontal and vertical beamwidth are calculated at the point where the main lobe decreases power by 3 dB.

  B. Vertical beamwidth is displayed (in degrees) on the antenna's Azimuth chart.

  C. When antenna gain is lower, the beamwidth is also lower in both the horizontal and vertical dimensions.

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

  Correct Answer: A

• Question 85:

  You are planning for PoE in a standard office deployment. Which one of these devices is least likely to be a PoE PD?

  A. Video camera

  B. Access point

  C. VoIP phone

  D. Ethernet switch

  Correct Answer: D

• Question 86:

  You are reporting on the RF environment in your facility. The manager asks you do describe the noise floor noted on the report. Which of the following is the best explanation?

  A. The energy radiated by flooring materials that causes interference in the 2.4 GHz and 5 GHz bands.

  B. The noise caused by elevators, microwave ovens, and video transmitters.

  C. The RF energy that exists in the environment from intentional and unintentional RF radiators that forms the baseline above which the Intentional signal of your WLAN must exist.

  D. The extra energy radiated by access points and client devices beyond that intended for the signal.

  Correct Answer: C

  Reference

  http://blog.prosig.com/2008/04/14/what-is-db-noise-floor-dynamic-range/

• Question 87:

  What statement about 802.11 WLAN bridges is true?

  A. WLAN bridges only work in the 2.4 GHz frequency band and they support only SISO communications

  B. WLAN bridges must use a channel with acceptable SNR at both transceivers to maintain the desired data rate bi-directionally

  C. WLAN bridges may support MIMO communications, but only if used in the 5 GHz frequency band

  D. WLAN bridges must be implemented such that no interference occurs on the channel anywhere between the two endpoints used to establish the bridge

  Correct Answer: C

• Question 88:

  You recently purchased four laptops containing dual-band 802.11ac adapters. The laptops can connect to your 2.4 GHz network, but they cannot connect to the 5 GHz network. The laptops do not show the 5 GHz SSIDs, which are different than the 2.4 GHz SSIDs. Existing devices can connect to the 5 GHz SSIDs with no difficulty. What is the likely problem?

  A. Interference from non-Wi-Fi sources

  B. Faulty drivers

  C. DoS attack

  D. Interference from other WLANs

  Correct Answer: D

• Question 89:

  An RF sigma sometimes bends as it passes through some material other than free space. What is the term that describes this behavior?

  A. Reflection

  B. Refraction

  C. Scattering

  D. Warping

  Correct Answer: B

• Question 90:

  Three access points are used within a facility. One access point is on channel 11 and the other two are on channel 1. The two access points using channel 1 are on either side of the access point using channel 11 and sufficiently apart so that they do not interfere with each other when they transmit frames. Assuming no other APs are in the vicinity, is CCI still a possibility in this network and why?

  A. Yes, because the client devices connected to one of the channel 1 APs will transmit frames that reach the other channel 1 AP as well as clients connected to the other channel 1 AP.

  B. No, because the APs are far enough apart that no CCI will occur.

  C. No, because CCI only occurs in the 5 GHz frequency band.

  D. Yes, because channel 11 loops around and causes CCI with channel 1.

  Correct Answer: A