802.11 Protocols And Devices

Front 1

When deploying lightweight access points, where does the integration service(IS) and distribution system service (DSS) occur?

Back 1

WLAN controller

Front 2

When deploying autonomous access points, where does the integration service(IS) and distribution system service (DSS) occur?

Back 2

Autonomous AP

Front 3

A lightweight access point that has the ability to operate as either as a 2.4 GHz transceiver or as a 5GHz transceiver, but cannot operate on both frequency bands at the same time, uses what type of radio?

Back 3

Single defined radio (SDR)

Front 4

What are some of the possible features of a WLAN controller?

Back 4

firewall, wireless intrusion detection system server, layer 3 switch and captive portal

Front 5

Name some possible capabilities of a WLAN controller?

Back 5

IP tuneling, virtual BSSID, VLANs, AP management, user management, role base access control, layer 3 roaming, dynamic RF, and Bandwidth management

Front 6

What term best describes a WLAN architecture in which some of the MAC services are handled by the WLAN controller and some are handled by the lightweight AP?

Back 6

Split MAC

Front 7

What term best describes the use of either multiple WLAN controller or APs as data distribution gateways onto the wired network?

Back 7

Distributed Data Forwarding (DDF)

Front 8

What type of WLAN controller solution deploys the controller at the access layer with 16 APs and sector antennas all in one unit that is mounted on the ceiling?

Back 8

WLAN array

Front 9

What term best describes a WLAN architecture that consists of groups of autonomous APs with WLAN controller intelligence and capability?

Back 9

Cooperative control access point (CC-AP)

Front 10

What type of serve can track the location of any 802.11 radio device as well as active Wi-Fi RFID tags with great accuracy?

Back 10

Real-Time location system (RTLS) server

Front 11

What type of service makes connections among the internal telephones of a private company and also connects them to the public switched telephone network (PSTN) via trunk lines?

Back 11

Privacy Branch Exchange (PBX)

Front 12

What is a commonly used network protocol that can be used to encapsulate an 802.11 frame inside an IP tunnel,creating a virtual point to point link between the lightweight AP and the WLAN controller?

Back 12

Genetic Routing Encapsulation (GRE)

Front 13

An 802.11 wireless network name is known as what type of address?

Back 13

SSID, ESSID

Front 14

What two 802.11 topologies require the use of an AP?

Back 14

BSS, ESS

Front 15

What factors might affect the size of a BSA coverage of an AP?

Back 15

The size and shape of a basic service area depend on AP power, antenna gain and physical surrounding.

Front 16

What components make up a distribution system (DS)?

Back 16

The distribution system medium(DSM) is a logical physical medium used to connect AP.
The distribution system service(DSS) consist of services built inside an AP, usually in the form of software.

Front 17

The 802.11 standard defines wireless wide area networking?

Back 17

NO, wireless local area networking

Front 18

What term best describe the logical name of basic service set (ESS)?

Back 18

Service set identifier (SSID) and Extended Service set identifier (ESSID)

Front 19

What are the services sets defined by the 802.11 standard?

Back 19

Basic Service set (BSS), Extended Service set (ESS), Independent basic Service set (IBSS) and quality of service basic service set (QBSS)

Front 20

What term describes one or more APs connected by a distribution system medium?

Back 20

ESS

Front 21

What term describes one or more client stations using peer-to-peer communications without an AP??

Back 21

Independent basic Service set (IBSS)

Front 22

What is a network name comparable to a Windows workgroup name that is used to describe a WLAN?

Back 22

SSID

Front 23

How much cell coverage overlap is needed for wireless repeaters?

Back 23

50 %

Front 24

What are two possible configuration modes for a client station?

Back 24

Infrastructure, Ad Hoc

Front 25

What are the two names for IBSS?

Back 25

Ad Hoc, Peer to Peer

Front 26

What is the term that describes AP using wireless backhaul?

Back 26

Wireless distribution system (WDS)

Front 27

How many MAC address are in the L2 header of a WDS frame?

Back 27

four

Front 28

what does acronym MSDU stand for?

Back 28

MAC Service Data Unit

Front 29

what does acronym MPDU stand for?

Back 29

Mac Protocol Data Unit

Front 30

what does acronym PSDU stand for?

Back 30

Physical Service Data Unit

Front 31

what does acronym PPDU stand for?

Back 31

Physical Protocol Data Unit

Front 32

what does acronym PLCP stand for?

Back 32

Physical Layer Convergence Procedure

Front 33

When Network layer sends data to the Data Link layer, it is handed off to the LLC. What does the data become known as?

Back 33

MSDU

Front 34

When the LLC sends the MSDU to the MAC sublayer, the header is added to it. What does the data become known as?

Back 34

MPDU

Front 35

What is the upper layer of the Physical layer known as?

Back 35

Physical Layer Convergence Procedure (PLCP)

Front 36

What is the lower layer of the Physical layer knows as?

Back 36

Physical Medium Dependent (PMD)

Front 37

What prepares the frames for transmission by taking the frame from the MAC sublayer and creating PPDU?

Back 37

Physical Layer Convergence Procedure (PLCP)

Front 38

What layer modulates and transmits the data as bits?

Back 38

PMD (Physical Medium Dependent )

Front 39

What is the PLCP service data unit also known as?

Back 39

MPDU

Front 40

Normally, if fragmentation is used with in BSS, MAC overhead will go ___, and network throughput will go____.

Back 40

UP, DOWN

Front 41

What do management frames carry?

Back 41

Information field and Information elements

Front 42

In a noisy environment, if fragmentation is used with in BSS, MAC overhead will go ___, and network throughput will go____.

Back 42

UP , UP

Front 43

What types of frames are used to joint and leave 802.11 networks?

Back 43

Management frames

Front 44

Do all data frames carry an MSDU payload?

Back 44

NO, Null function frame

Front 45

What is passive scanning?

Back 45

client station listens for a beacon frames

Front 46

What is active scanning?

Back 46

client station sends a probe request and listens for the probe response.

Front 47

Required data rates are also known as what?

Back 47

Basic data rates

Front 48

What do priority tags provide a mechanism for?

Back 48

Quality of service (QoS)

Front 49

When a Hybrid Coordination Function (HCF) radio contends for the medium, it receives an allotted amount of time to send frames known as what ?

Back 49

Transmit opportunity (TXOP)

Front 50

What two channel access method are created by HCF?

Back 50

Extended Distributed channel Access (EDCA) and HCF Controlled Channel Access(HCCA)

Front 51

Name the four main components of Distributed Coordination Function(DCF)

Back 51

NAV (network allocation vector)/ virtual carrier sense, CCA (clear channel Assessment)/physical carrier sense, DIFS, random back off time

Front 52

What three coordination functions are defined by 802.11 CSMA/CA?

Back 52

Distributed Coordination Function, Point Coordination Function and Hybrid Coordination function

Front 53

Which Wi-Fi Alliance certification defines enhanced mechanisms to conserve battery power for devices using Wi-Fi radio by managing the time the client devices spends in sleep mode?

Back 53

WMM-PS

Front 54

What WLAN topology requires four MAC addresses(source, destination, transmitter and receiver) when transmitting an 802.11 frame?

Back 54

Wireless distribution system (WDS))

Front 55

The 802.11n draft amendment defines High Throughput(HT) clause 20 radios that make use of _____ antenna technology in unison with ______RF technology.

Back 55

MIMO,OFDM

Front 56

What term best describes a single radio and all of its supporting architecture including mixers, amplifiers and analog/digital converters?

Back 56

Radio chain

Front 57

A 3x4 MIMO system uses four radios. Three radios are used as _____, and four radio are used as _____.

Back 57

Transmitters, receivers

Front 58

What term is used to describe multiple streams of data following different path to a receiver?

Back 58

spatial diversity

Front 59

what is another term used to describe sending multiple independent stream when using spatial diversity?

Back 59

spatial multiplexing (SM)

Front 60

What is the term used to describe multiple spatial streams of data using different modulation rates?

Back 60

Unequal modulation

Front 61

what is the signal processing technique that may be used to linearly combine signals during receive diversity?

Back 61

Maximal ratio combining (MRC)

Front 62

What technology is defined by the 802.11n amendment that controls that phase of signals transmitted from multiple antennas and has the affect of emulating a high-gain unidirectional antenna?

Back 62

Transmit beamforming (TxBF)

Front 63

A 40 MHz HT channel uses 114 OFDM subcarriers. How many are used to transmit data, how many are used as pilot subcarriers?

Back 63

108/6

Front 64

What is the period of time between symbols that accommodates for the late arrival of symbols over long paths?

Back 64

Guard interval (GI)

Front 65

The 802.11n amendment defines the use of HT clause 20 dios that use a mandatory_____-nanosecond guard and an optional ____-nanosecond guard interval.

Back 65

800/400

Front 66

Name three factor used by an HT clause 20 radio modulation coding scheme(MCS) to determine a data rate.

Back 66

Modulation type, number of spatial streams, and the guard interval

Front 67

Which 802.11n PPDU format is not compatible with non-HT radio transmissions?

Back 67

HT Greenfield

Front 68

Which 802.11n PPDU format is backward compatible with non-HT radio transmission?

Back 68

HT Mixed

Front 69

What are the two types of frame aggregation defined by the 802.11n amendment?

Back 69

A-MSDU and A-MPDU

Front 70

Which frame aggregation method is used when the multiple payloads have different destination addresses?

Back 70

A-MPDU

Front 71

Which frame aggregation method can encrypt the frame payloads independently?

Back 71

A-MSDU

Front 72

Which frame aggregation method requires the use of multiple traffic ID block acknowledgment?

Back 72

A-MPDU

Front 73

What us the interframe space is used during a frame burst in an HT Greenfiled wireless LAN?

Back 73

Reduced interframe space (RIFS)

Front 74

What is the power management method used by a MIMI system to power down all but one single radio?

Back 74

Spatial Multiplexing Power Save (SMPS)

Front 75

What are the two methods of operation of SM power save?

Back 75

static and dynamic

Front 76

The 802.11n amendment defines an optional mode of operation that divides time and alternates between 20MHz and 40 MHz transmissions. What is the name of this optional mode?

Back 76

Phased coexistence operation (PCO)

Front 77

If 20/40 -capable stations transmit by using a single 20 MHz channel, they must transmit on which 20 MHz channel?

Back 77

Primary

Front 78

What are the two methods of power management defined by the 802.11n amendment?

Back 78

spatial multiplexing power save (SMPS)
power save multi poll
(PSMP)