Chapter 6 Test 2
1) Wireless network standards operate at ________. A) the data link layer B) the Internet layer C) both A and B D) neither A nor B
A
11) A cellular telephone uses a(n) ________. A) omnidirectional antenna B) dish antenna C) both A and B D) neither A nor B
A
13) What propagation problem is especially bad in moist air? A) absorptive attenuation B) electromagnetic interference C) multipath interference D) inverse square law attenuation
A
19) To handle multiple conversations in radio transmission, you normally use multiple ________. A) channels B) frequencies C) service bands D) wires
A
2) Wireless network standards are ________ standards. A) OSI B) TCP/IP C) both A and B
A
27) Companies are moving to the 5 GHz band because there is ________ than in the 2.5 GHz band. A) more bandwidth B) less absorptive attenuation C) both A and B D) neither A nor B
A
29) Spread spectrum transmission is used in WLANs because ________. A) it is required by regulators B) it offers strong security C) both A and B D) neither A nor B
A
32) In unlicensed bands, ________. A) you can use radios wherever you please B) you can prevent nearby businesses from setting up access points in the same channel C) both A and B D) neither A nor B
A
35) Access points take ________ from wireless devices and send them on to devices on the wired LAN. They also do the converse. A) packets B) frames C) both A and B D) neither A nor B
A
37) A single access point and the set of hosts it serves is called a(n) ________. A) BSS B) BSSID C) ESS D) none of the above
A
39) To use an access point, you need to know its ________. A) SSID B) BSSID C) ESSID D) Wi-Fi ID
A
40) To connect to an access point, you must know its ________. A) SSID B) EUI-48 address C) IP address D) Wi-Fi ID
A
42) In an extended service set, each access point ________. A) must have the same SSID B) must have different SSIDs C) must have coordinated SSIDs D) none of the above
A
44) The standard for roaming among access points is ________. A) 802.11r B) 802.11s C) 802.11W D) the wireless handoff protocol
A
45) What happens if two nearby access points use the same channel? A) They will interfere with each other. B) They will be bonded for joint operation automatically. C) They will be bonded for joint operation automatically if they are on the same ESS. D) They will be bonded for joint operation automatically if they have the same SSID.
A
46) There is an access point that serves eight wireless hosts. On how many channels will these devices transmit and receive during the course of an hour or two? A) 1 B) 2 C) 8 D) 9
A
53) CSMA/CA+ACK usually is ________. A) mandatory B) optional C) not important D) efficient
A
54) Which of the following is more efficient and faster? A) CSMA/CA+ACK B) RTS/CTS C) Both are about equally efficient and fast.
A
55) Which of the following is the newest Wi-Fi standard? A) 802.11ac B) 802.11g C) 802.11n D) 802.11b
A
57) Wider channel bandwidth ________. A) increases transmission speed B) allows more channels to be used in a service band C) both A and B D) neither A nor B
A
6) Compared to wired transmission, propagation problems in radio transmission are ________. A) worse B) about as bad C) better
A
62) MIMO ________. A) increases throughput B) lowers propagation distance C) both A and B D) neither A nor B
A
10) The other wireless device is far away in a known direction. It would be better to use ________. A) an omnidirectional antenna B) a dish antenna C) neither A nor B
B
14) What propagation problem becomes worse as there is a large and dense object between sender and receiver? A) multipath interference B) shadow zones or dead zones C) both A and B D) neither A nor B
B
20) Signals in a transmission usually ________. A) travel at a single frequency B) spread over a range of frequencies C) spread over the entire frequency distribution D) spread over the entire service band
B
24) To transmit data very rapidly, you would want a ________ channel. A) narrowband B) broadband C) single-frequency band D) none of the above
B
26) The 2.4 GHz band supports ________ possible non-overlapping 20 MHz channel(s). A) 1 B) 3 C) 7 D) 11
B
30) Spread spectrum transmission is used in WLANs for ________. A) higher transmission speed B) more reliable transmission C) greater security D) more efficient transmission
B
31) WLANs normally use ________. A) licensed bands B) unlicensed bands C) both A and B D) neither A or B
B
36) A wireless host sends a packet to a server on the company's wired Ethernet LAN via an access point. How many frames will be involved in this one-way transmission? A) 1 B) 2 C) 4 D) There will be one frame for each switch along the way.
B
38) ________ have SSIDs. A) Wireless clients B) Wireless access points C) both A and B D) neither A nor B
B
43) Access points in the same ESS communicate via ________. A) wireless transmission B) the distribution system C) a master access point D) routers
B
5) Wireless access points typically link wireless clients to ________. A) wireless servers B) servers on the wired network C) both A and B
B
50) CSMA/CD+ACK is ________. A) unreliable B) reliable C) semireliable
B
52) The 802.11 standard has two mechanisms for media access control. One of two mechanisms is mandatoryit is ________. A) MAC B) CSMA/CA+ACK C) RTS/CTS D) CSMA/CD
B
58) Which of the following only operates in the 5 GHz band? A) 802.11b B) 802.11ac C) 802.11g D) 802.11n
B
60) In the 5 GHz band, how many channels can you have with 802.11ac with 80 GHz channels? A) 1 B) 6 C) 12 D) 24
B
7) Wireless radio transmission speed is usually measured in terms of ________. A) wavelength B) frequency C) amplitude D) wetness
B
8) Frequency is measured in terms of ________. A) nanometers B) hertz C) microns D) microseconds
B
22) To transmit very rapidly in RADIO, you need ________. A) single-frequency transmission B) single-mode transmission C) wide bandwidth D) narrow bandwidth
C
23) Channels with wide bandwidths are called ________ channels. A) multimode B) full-duplex C) broadband D) parallel
C
25) 802.11 standards are being developed to work in the ________ unlicensed band. A) 2.4 GHz B) 5 GHz C) both A and B D) neither A nor B
C
3) Wi-Fi Standards come from the ________ Working Group. A) 802.1 B) 802.3 C) 802.11 D) 802.1X
C
33) A channel has more bandwidth than is necessary given data transmission speeds requirements in ________ transmission. A) normal radio B) reliable commercial C) spread spectrum D) licensed
C
34) Which of the following uses OFDM? A) 802.11ac B) 802.11n C) both A and B D) neither A nor B
C
4) We use the terms Wi-Fi and ________ interchangeably in this book. A) 802.1 B) 802.3 C) 802.11 D) 802.1X
C
41) An extended service set (ESS) is a group of BSSs that ________. A) are connected to the same distribution system B) have the same SSID C) both A and B D) neither A nor B
C
48) Media access control governs transmission by ________. A) access points B) wireless hosts C) both A and B D) neither A nor B
C
49) In CSMA/CD+ACK, when a wireless NIC wishes to transmit, it listens for traffic. If there is traffic, it waits. When the traffic stops, it may transmit immediately. A) always true B) sometimes true C) always false
C
59) In 802.11g, channel bandwidth usually is ________. A) 20 GHz B) 40 GHz C) 20 MHz D) 40 MHz
C
63) Beamforming can allow an access point to ________. A) direct power to individual clients B) send signals to two different clients at the same time C) both A and B D) neither A nor B
C
9) Radio transmission is measured in terms of ________. A) bytes per second B) wavelength C) frequency D) bits per second
C
12) At 10 meters, a signal has a strength of 100 mW. About how strong will it be at 40 meters? A) about 0.5 mW B) about 5 mW C) about 25 mW D) about 6 mW
D
15) The most serious problem with wireless transmission in WLANs is ________. A) inverse square law attenuation B) absorptive attenuation C) shadow zones D) multipath interference
D
16) What propagation problem becomes worse as frequency increases? A) inverse square law attenuation B) electromagnetic interference C) both A and B D) neither A nor B
D
17) The frequency spectrum extends ________. A) into the gigahertz range B) into the visible light range C) into the ultraviolet range D) to infinity
D
18) 2.4 GHz and 5 GHz are ________. A) frequency spectrums B) broadbands C) channels D) service bands
D
21) A channel extends from 55 MHz to 60 MHz. Its bandwidth is ________. A) 60 MHz B) 55 MHz C) 65 MHz D) none of the above
D
28) The 5 GHz band usually supports about ________ non-overlapping 20 MHz channel(s). A) 1 B) 3 C) 7 D) 12
D
47) ________ is a technique for preventing two wireless stations from transmitting at the same time and therefore interfering with each other. A) Creating extended service sets B) Roaming C) The distribution system D) Media access control
D
51) In ________, when a wireless host wishes to send, it first sends a message to the wireless access point asking for permission to send. When the access point sends back a response, the host sending the original message may transmit. All other hosts must wait. A) CSMA/CA+ACK B) CSMA/CA C) CSMA/CD D) RTS/CTS
D
56) Today, Wi-Fi sales are dominated by ________. A) 802.11a B) 802.11g C) 802.11n D) 802.11ac
D
61) MIMO ________. A) bonds two or more channels for higher speed B) is used in all forms of 802.11 C) uses a single spatial stream but multiple signals D) transmits multiple signals in the same channel
D