802.11 Standards

Question 1

At what layer does 802.11 technology specifies?

Answer 1

Physical and Mac Sublayer of Data like layer

Question 2

What was obsolete in 802.11 standard?

Answer 2

Infrared Medium

Question 3

_______ Signal can be defined as narrow band or spread spectrum ?

Answer 3

Frequency hoping spread Spectrum (FHSS)

Question 4

What is a spread spectrum ?

Answer 4

When band width is wider than data what is required to carry data

Question 5

Which spectrum technology used Fixed channel ?

Answer 5

Direct sequence spread spectrum

Question 6

Which amendment was created as single document including 8 amendment? In which year ?

Answer 6

802.11-2007 Amendment

Question 7

What frequency is used in 802.11a

Answer 7

5Ghz

Question 8

What is the RF technology used ?

Answer 8

Orthogonal frequency Division Multiplexing (OFDM)

Question 9

Initially 5Ghz radio transmitted in ?

Answer 9

Three different 100MHz channel

Question 10

What are these three band called ?

Answer 10

Unlicensed National Information Infrastructures (U-NII) frequency band

Question 11

How many bands are available now ?

Answer 11

12

Question 12

What technology does 802.11b use ?

Answer 12

High rate Direct Sequence Spread Spectrum (HR-DSSS)

Question 13

What is the frequency space of 802.11b ?

Answer 13

2.4GHz -2.4835 GHz ISM Band

Question 14

What does ISM mean ?

Answer 14

Industrial , Scientific, Medical

Question 15

What technology does 802.11g use ?

Answer 15

Extended Rate Physical (ERP)
ERP- OFDM
ERP-DSSS/CCK (Complementary Code keying)

Question 16

What frequency band did 802.11g use ?

Answer 16

2.4GHz-2.4835 GHz ISM Band

Question 17

What data rates are possible in 802.11g ?

Answer 17

6,9,12,18,24,36,48,54

Question 18

Why data rates of 6,12,24 are only used ?

Answer 18

For backward capabilities

Question 19

Data rates in 802.11b ?

Answer 19

DSSS - 1, 2 Mbps

HR-DSSS - 5.5,11 Mbps

Question 20

Data rates in 802.11g?

Answer 20

ERP DSSS/ CCK - 1,2,5.5 and 11
ERP OFDM- 6,12,24
Also supported 9,18,36,48,54

Question 21

What are the mandatory data rates in 802.11a ?

Answer 21

6,12 and 24

Question 22

Which year did legacy 802.11 ratified ?

Answer 22

1997

Question 23

Which year did 802.11b ratified ?

Answer 23

1999, HR (2003)

Question 24

Which year did 802.11g ratified ?

Answer 24

2003

Question 25

Which year did 802.11a ratified ?

Answer 25

1999

Question 26

Key component of Wireless Security ?

Answer 26

Data privacy Data integrity Authentication

Question 27

What was the encryption system used in 802.11 ?

Answer 27

64-bit static encryption called Wired Equivalent Privacy (WEP)

Question 28

What was the new securty amendment?

Answer 28

802.11i

Question 29

What does it defined ?

Answer 29

A Robust Security Network (RSN)

Question 30

What encryption was used for data privacy and confidentiality in 802.11i ?

Answer 30

Counter mode with Cipher Block Chaining messege authentication Code protocol (CCMP)

Question 31

What algorithm does CCMP use ?

Answer 31

Advanced Encryption Standard (AES) Algorithm

Question 32

What methods were used for authentication in IEEE 802.1x?

Answer 32

Authorisation framework or pre-shared keys (PSK)

Question 33

What did 802.11x solution required ?

Answer 33

An Extensible Authentication Protocol (EAP)

Question 34

Did 802.11i specified any EAP method?

Answer 34

No

Question 35

What does Robust Security Network defines ?

Answer 35

Entire method of establishing Authentication, negotiating security association and dynamically generating encryption keys for client and access points

Question 36

What technology was used in 802.11r ?

Answer 36

Fast secure roaming

Question 37

What was 802.11w frames refered as ?

Answer 37

Robust Management Frame

Question 38

How robust management frame protected ?

Answer 38

By Robust management frame protection service

Question 39

What technology used is 802.11n ?

Answer 39

MIMO- OFDM

Question 40

What is 802.11n know as ?

Answer 40

High throughput (HT)

Question 41

What rates does 802.11n support ?

Answer 41

600Mbps

Question 42

Benefits of MIMO technology?

Answer 42

Increased throughput and greater range

Question 43

802.11n exists in which layer using MIMO?

Answer 43

Physical

Question 44

MIMO used multiple radios and Antenna known as ?

Answer 44

Radio chain

Question 45

Which method is used Transmitting Multiple stream of data in MIMO?

Answer 45

Spatial Multiplexing (SM)

Question 46

Use of multiple receiver in MIMO increases ?

Answer 46

SNR

Question 47

What diversity technique is used to transmit and receive data?

Answer 47

Space time block coding (STBC) | Cyclic shift diversity (CSD)

Question 48

Can MIMO send individual unique data stream ?

Answer 48

Yea

Question 49

What are indipendent data stream known as ?

Answer 49

Spatial Stream

Question 50

What is MIMO diversity?

Answer 50

Method of using multiple antenna to survive the negative effect of multipath

Question 51

What is MIMO diversity?

Answer 51

Method of using multiple antenna to survive the negative effect of multipath

Question 52

What is STBC ?

Answer 52

Space Time block Coding , A method where same information is transmitted on two or more Antenna.

Question 53

When is STBC used ?

Answer 53

When the number of radio chains exceed the number of spatial stream

Question 54

Where is CSD used ?

Answer 54

In 802.11g and 802.11a devices | For mixed mode deployment- 802.11n coexist with 802.11g and 802.11a

Question 55

What does transmit Beamforming relies on ?

Answer 55

Implicit feedback and Explicit feedback

Question 56

What does transmit Beamforming relies on ?

Answer 56

Implicit feedback and Explicit feedback

Question 57

What can be used as Sounding frame ?

Answer 57

Any frame

Question 58

What can be used as Sounding frame ?

Answer 58

Any frame