Why is it recommended for a wireless network administrator to disable 1 Mbps and 2 Mbps data rates on the WLAN infrastructure? (Choose two)
A. To improve capacity in the BSS
B. To reduce the size of the AP's effective service area
C. To prevent 802.11b devices from associating
D. To maximize the range of the highest data rates
E. To prevent VoWiFi multicast frames
F. To enable support for long preambles
What factor is NOT taken into account when calculating the Link Budget of a point-to-point outdoor WLAN bridge link?
A. Operating frequency
B. Transmit antenna gain
C. Transmit power
D. Antenna height
E. Receive sensitivity
F. Distance
Given: Two co-located 802.11b/g/n APs can interfere with one another and cause contention and collisions, even when the two APs are operating on non-overlapping channels (e.g. 1 and 6).
What deployment flaw could cause this problem? (Choose two)
A. The access points are mounted too closely to one another.
B. Reflective objects in the area are causing significant multipath.
C. A client station is using active scanning to probe for access points on multiple channels.
D. The output power on the access points is too high.
E. A client station authenticates to both access points, but does not associate.
F. The access points are not synchronized to the same NTP server.
Given: As defined in the 802.11 specification, legacy Power Save requires an inefficient back-and-forth frame exchange process. Due to this inefficiency, many WLAN device implementations use a variation of
802.11 Power Save to accomplish the same function.
What non-standard power save behavior is used by most Wi-Fi devices in actual implementations?
A. Client devices ignore the TIM field and automatically send PS-Poll frames after every beacon.
B. After each beacon, the AP attempts to empty its frame buffer by sending Wake-on-WLAN frames to wake each dozing client.
C. Request-to-Send and Clear-to-Send frame exchanges are used to trigger the delivery of buffered data.
D. The Beacon interval is changed from the default 100 time units to 10 or less time units.
E. Clients send null data frames to the AP and switch the power management bit from 1 to 0 to receive queued data.
F. Stations send a CTS-to-self frame to the AP with a very long duration period so they can receive all of their buffered data at once.
In an 802.11b/g system, what channels are considered non-overlapping? (Choose two)
A. Channels 5 and 10
B. Channels 1 and 5
C. Channels 3 and 7
D. Channels 2 and 8
E. Channels 8 and 11
F. Channels 10 and 13
What problems may occur when there are hidden nodes in the BSS?
A. Increase in downlink (transmitted by AP) frame retries
B. High retransmission count for a subset of client stations
C. Use of frame fragmentation with fragment bursts
D. Excessive use of null data frames
E. Duration values vary widely in each data frame
What statement is true concerning the use of Orthogonal Frequency Division Multiplexing (OFDM) in IEEE
802.11 WLANs?
A. 802.11a and 11n use six (6) "pilot" subcarriers as a reference for the receiver to detect frequency and phase shifts of the signal.
B. 802.11a/g/n OFDM includes several combinations of modulation and coding to achieve data rates from 1-600 Mbps.
C. With 802.11a OFDM, 16-QAM provides either 48 or 54 Mbps data rates, depending upon coding rates.
D. 802.11n HT-OFDM utilizes 256-QAM, which increases the data rate from 54 Mbps (with 64-QAM) up to 65 Mbps.
E. In 802.11a OFDM, forty-eight (48) subcarriers are used as parallel symbol transmission paths to carry data.
What term correctly completes the following sentence?
802.11a/b/g used a mandatory 800ns guard interval. 802.11n introduces an optional short 400ns guard interval. Guard intervals (GI) are necessary in OFDM to reduce the likelihood of interference between two consecutive ____________.
A. Frames
B. Packets
C. Segments
D. Bits
E. Bytes
F. Symbols
Given:
As a consultant, you have been hired by ABC Company to implement an outdoor WLAN connection
between two buildings that are 2 kilometers (1.24 miles) from each other, with no obstructions in between.
Your first required objective is to create a point-to-point link between the two buildings within the local regulatory body's 800 mW EIRP maximum.
Your second required objective is to provide an industry-standard security solution capable of supporting mutual authentication.
As an optional objective, you must minimize the amount of interference from, and to, nearby WLAN networks.
You install an OFDM wireless bridge at each building, configuring one in root mode and the other in non-root mode. You set each radio for 100 mW (20 dBm) and attach 9 dBi omni-directional antennas to both. You configure the network for WPA2-Enterprise with PEAPv0/EAP-MSCHAPv2 authentication.
Which statement is true about the solution you chose to deploy?
A. Your solution meets both required objectives and the optional objective.
B. Your solution meets the first required objective and the optional objective, but not the second objective.
C. Your solution meets the second required objective and the optional objective, but not the first required objective.
D. Your solution meets neither required objective but meets the optional objective.
E. Your solution meets both required objectives, but does not meet the optional objective.
F. Your solution does not meet either required objective, or the optional objective.
In an infrastructure Basic Service Set (BSS), how does the passive scanning process occur?
A. Access points broadcast Beacons on all channels of each radio within the regulatory domain. Nearby client stations record information found in the Beacons for use in the association process.
B. Client stations broadcast Probe Request frames on all supported channels in the regulatory domain. Nearby access points respond with Probe Response frames. Client stations record information in the Probe Response frames for use in the association process.
C. Client stations broadcast Probe Request frames on the single channel for which they are programmed. Nearby access points respond on that channel with Probe Response frames. Clientstations record information found in the Probe Response frames for use in the association process.
D. Access points broadcast Beacons on a single channel for which it is programmed. Nearby client stations listen for Beacon frames and record information found in the Beacons for use in the association process.
