Deck 13: Wireless Lans

Question 1

Enabling an employee returning from a trip to transfer data from a personal portable computer to a server in the office is an example of Nomadic access.

Answer 1

True

Question 2

A wireless LAN is defined as one that makes use of a wireless transmission medium.

Answer 2

True

Question 3

Employees linking their computers into a temporary network in a conference room for a meeting would be an example of ________ networking.

A)Nomadic
B)cross building interconnect
C)ad hoc
D)Lan extension

Answer 3

C

Question 4

Important characteristics of Barker sequences are their robustness against interference and their insensitivity to multipath propagation.

Question 5

The IEEE 802.11 standards do not include a specification of speed versus distance objectives.

Question 6

The ________ standard defines a set of services and physical layer options for wireless LANs.

A)IEEE 802.3
B)IEEE 802.11
C)IEEE 811.2
D)IEEE 802.10

Question 7

A hub topology,with a MAC algorithm such as CSMA to control,is appropriate for ad-hoc LANs.

Question 8

A wireless LAN must meet the same sort of requirements typical of any LAN,including high capacity,ability to cover short distances, full connectivity among attached stations,and broadcast capability.

Question 9

The IEEE 802.11 physical layer covers a limited range of data rates.

Question 10

A major disadvantage of IEEE 802.11n is that it is not upward compatible with 802.11a or 802.11b.

Question 11

The popularity of wireless LANs has not grown significantly because the problems of high prices,low data rates,occupational safety concerns,and licensing requirements have not been addressed.

Question 12

A typical coverage area for a wireless LAN has a diameter of ________.

A)50 to 225 m
B)25 to 200 m
C)100 to 300 m
D)75 to 250 m

Question 13

An individual cell of an IR LAN is limited to a single room because infrared light does not penetrate opaque walls.

Question 14

In a MIMO scheme the transmitter employs just a single antenna.

Question 15

A wireless LAN linked into a wired LAN on the same premises is referred to as a LAN ________.

A)interconnection
B)handoff
C)ad hoc
D)extension

Question 16

A user module acts as an interface to a wireless LAN..

Question 17

The most prominent specification for wireless LANs was developed by the IEEE 802.3 working group.

Question 18

Wireless LANs are not as vulnerable to interference and eavesdropping as wired LANs.

Question 19

________ antenna architecture is the most important of the enhancements provided by 802.11n.

A)MIMO
B)Nomadic
C)Directed-beam
D)OFDM

Question 20

OFDM LANs typically operate in either the 2.4-GHz band or the 5- GHz band.

Question 21

IEEE 802.11 defines three services that provide a wireless LAN with secure access and privacy services: authentication,privacy,and ________.

A)deauthentication
B)protected access
C)AP association
D)private access

Question 22

Within the United States,the FCC has authorized two unlicensed applications within the ISM band: ________ systems and very low power systems.

Question 23

________ access provides a wireless link between a LAN hub and a mobile data terminal equipped with an antenna,such as a laptop computer or notepad computer.

Question 24

"Recommended practice for the evaluation of 802.11 wireless performance" is the scope of the ________ standard.

A)IEEE 802.11,2
B)IEEE 802.11f
C)IEEE 802.11r
D)IEEE 802.11a

Question 25

Currently the most popular type of wireless LAN uses ________ techniques.

Question 26

The IEEE 802.11 ________ layer includes infrared and spread spectrum and covers a range of data rates.

Question 27

In the United States,________ microwave bands have been set aside for unlicensed spread spectrum use.

A)2
B)3
C)6
D)4

Question 28

Currently wireless LAN products fall into three categories: spread spectrum LANs,OFDM LANs and ________ LANs.

Question 29

IEEE ________ embodies changes in three general areas: use of MIMO, enhancements in radio transmission,and MAC enhancements.

Question 30

A ________ is a system used to interconnect a set of basic service sets and integrated LANs to create an extended service set.

A)DS
B)MPDU
C)AP
D)MSDU

Question 31

The lower sublayer of the MAC layer is the ________ which uses a contention algorithm to provide access to all traffic.

A)PCF
B)IFS
C)DCF
D)LLC

Question 32

Three physical media are defined in the original 802.11 standard: DSSS, FHSS,and ________.

A)GFSK
B)UNNI
C)infrared
D)Barker sequence

Question 33

The IEEE 802.11 services include managing associations,delivering data, and ________.

Question 34

In most cases,spread spectrum LANs operate in the ________ microwave bands so that no Federal Communications Commission licensing is required for their use in the United States.

Question 35

The primary service used by stations to exchange MAC frames when the frame must traverse the DS to get from a station in one BSS to a station in another BSS is ________.

A)association
B)integration
C)transition
D)distribution

Question 36

The principal technologies used for wireless LANs are spread spectrum, narrowband microwave,and ________.

Question 37

A number of changes are made in 802.11n in the radio transmission scheme to increase capacity.The most significant of these techniques is ________.

A)channel bonding
B)diffusion
C)interconnection
D)spread spectrum

Question 38

For higher speeds,a technology known as ________ is superior to spread spectrum.

A)ODC
B)OFDM
C)DCIR
D)DBIR

Question 39

The ________ module includes either bridge or router functionality to link the wireless LAN to the backbone.

Question 40

The ________ is a set of one or more interconnected BSSs and integrated LANs that appear as a single BSS to the LLC layer at any station associated with one of these BSSs.

A)DS
B)AP
C)MPDU
D)ESS

Question 41

In the IEEE 802 physical layer frame format the ________ field enables the receiver to acquire an incoming OFDM signal and synchronize the demodulator.

Question 42

The smallest building block of a wireless LAN is a ________ which consists of some number of stations executing the same MAC protocol and competing for access to the same shared wireless medium.

Question 43

To integrate the IEEE 802.11 architecture with a traditional wired LAN a ________ is used.The logic is implemented in a device,such as a bridge or router,that is part of the wired LAN and that is attached to the DS.

Question 44

The three MAC frame types are control frames,data frames,and ________ frames.

Question 45

An ________ is an entity that has station functionality and provides access to the distribution system via the wireless medium for associated stations.