PW0-270 무료 덤프문제 온라인 액세스

How long, in microseconds, is the required Slot Time that is announced by an AP in an HT BSS when HR/DSSS, ERP-OFDM, and HT-OFDM client stations are associated to the AP?

• A.4 (us)
• B.20 (us)
• C.2 (us)
• D.9 (us)
• E.10 (us)

What types of wireless systems are illustrated?

• A.An ERP IEEE 802.11 system using channel 6 and Bluetooth v1.2 discovery
• B.An 802.11 HR/DSSS system using channel 2 and a digital FHSS phone
• C.A 2.4 GHz cordless phone on channel 14 and a wireless RFID reader
• D.A Bluetooth v2.0 file transfer and a 40 MHz HT AP on channels 11, 7 (primary, secondary)

According to the IEEE 802.11 standard, what is one structural difference between a MAC Protocol Data Unit (MPDU) and a MAC Management Protocol Data Unit (MMPDU)?

• A.The MMPDU frame body is limited to 300 bytes, whereas the MPDU frame body can carry up to 2304 bytes.
• B.The MPDU frame's FCS field is 4 bytes, while the MMPDU frame's FCS field is 8 bytes.
• C.The MPDU header always places the BSSID in the first address field, but in the MMPDU the BSSID can be found in any of the address fields.
• D.Both the MPDU and MMPDU have a QoS Control (QC) field, but all bits of the MMPDU's QC field are always 0.
• E.An MMPDU header may only contain three address fields, but an MPDU may have four address fields.

In the frame decode shown, there are two sets of supported data rates. 1, 2, 5.5, and 11 Mbps are all shown as "basic" data rates, and 6, 9, 12, 18, 24, 36, 48, and 54 Mbps are shown simply as supported data rates.

What is true of "basic" data rates in this context?

• A.The highest data rate set to Basic is automatically used to send broadcast traffic such as Beacon frames.
• B.Basic rates are optional data rates for the BSS, often used for assuring connectivity for legacy stations.
• C.Basic rates are only used for multicast traffic, and do not affect unicast traffic.
• D.Basic rates are defined in an AP's service set to specify mandatory data rates for all retry frames.
• E.The AP requires all client stations to support Basic rates in order to associate to its BSS.

Given: Before installing a Wi-Fi network, ABC Company performed a spectrum analysis looking for problems. The 2.4 GHz RF spectrum looked like Image-A. After installing an ERP WLAN, ABC Company performed another spectrum analysis during business hours. The 2.4 GHz RF spectrum then looked like Image-B close to an AP on channel 1.

Now the 2.4 GHz RF spectrum looks like Image-C and access points and clients can no longer communicate on channel 1. What is happening on channel 1?

• A.The shape of the signals in images B and C indicates that a licensed user in this frequency range has enabled the "guard bands" in an effort to restrict local interference with other systems.
• B.A high-power, narrowband RF interference source on channel 1 is causing the CCA energydetects(ED) function on 802.11 devices to indicate a busy medium because the signal source is above the ED threshold.
• C.The access point's antenna connectors have been tampered with, causing "spike and shear" RF transmissions that are not compatible with the OFDM PHY format. For that reason, client devices cannot receive the AP's transmissions without error.
• D.Detection of a DFS radar event has discontinued 802.11 operation on channel 1, but the access point's Channel Switch Announcement frame cannot be sent due to the presence of radar.
• E.Stronger transmissions from licensed 2.4 GHz users, such as HAM operators, are compressing the transmissions from the channel 1 access points into the lower portion of the band.