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- CWNA-107
51.
The Fresnel zone should not be blocked by more than what percentage to maintain
a reliable communications link?
- A.20 percent
- B.40 percent
- C.50 percent
- D.60 percent
- Answer & Explanation
- Report
Answer : [B]
Explanation :
Explanation :
| Any more than 40 percent encroachment into the Fresnel zone is likely to make a link unreliable. The clearer the Fresnel zone, the better, and ideally it should not be blocked at all. |
52.
The size of the Fresnel zone is controlled by what factors? (Choose all that apply.)
- A.Antenna beamwidth
- B.RF line of sight
- C.Distance
- D.Frequency
- Answer & Explanation
- Report
Answer : [C, D]
Explanation :
Explanation :
| The distance and frequency determine the size of the Fresnel zone; these are the only variables in the Fresnel zone formula. |
53.
When a long-distance point-to-point link is installed, earth bulge should be considered
beyond what distance?
- A.5 miles
- B.7 miles
- C.10 miles
- D.30 miles
- Answer & Explanation
- Report
Answer : [B]
Explanation :
Explanation :
| The distance when the curvature of the earth should be considered is 7 miles. |
54.
A network administrator replaced some coaxial cabling used in an outdoor bridge
deployment after water damaged the cabling. After replacing the cabling, the network
administrator noticed that the EIRP increased drastically and is possibly violating the
maximum EIRP power regulation mandate. What are the possible causes of the increased
amplitude? (Choose all that apply.)
- A.The administrator installed a shorter cable.
- B.The administrator installed a lower-grade cable.
- C.The administrator installed a higher-grade cable.
- D.The administrator installed a longer cable.
- E.The administrator used a different-color cable.
- Answer & Explanation
- Report
Answer : [A, C]
Explanation :
Explanation :
| Installing a shorter cable of the same grade will result in less loss and thus more amplitude being transmitted out the antenna. A higher-grade cable rated for less dB loss will have the same result. |
55.
Which of the following are true for antenna diversity used by 802.11a/b/g access points?
(Choose all that apply.)
- A.The transceiver combines the signal from both antennas to provide better coverage.
- B.Transceivers can transmit from both antennas at the same time.
- C.The transceiver samples both antennas and chooses the best received signal from one antenna.
- D.Transceivers can transmit from only one of the antennas at a time.
- Answer & Explanation
- Report
Answer : [C, D]
Explanation :
Explanation :
| A transceiver using antenna diversity can transmit from only one antenna at a time. If it transmitted from both antennas, the two signals would interfere with each other. A transceiver can also interpret only one signal at a time, so it samples the sig- nals received by both antennas and chooses the better signal to be received. |
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