Chapters 13 - 14

Question 1

What is 802.11?

Answer 1

It is the international standard for wireless networking

Question 2

What does GHz stand for?

Answer 2

gigahertz

Question 3

What are the two main Wi-Fi frequency ranges?

Answer 3

2.4 GHz and 5 GHz

Question 4

What normal Wi-Fi channels exist (in the USA)?

Answer 4

1 - 11

Question 5

What is Channel 196?

Answer 5

It is a channel in the 5 GHz range.

Question 6

What is a site survey?

Answer 6

You check for Wi-Fi signals that already exist.

Question 7

In networking, what does sniff mean?

Answer 7

Sniff means listen to the network trac and try to learn from it.

Question 8

What channels are commonly usable (in the USA)?

Answer 8

1, 6, and 11

Question 9

Why are many Wi-Fi channels not used?

Answer 9

There is too much signal bleed between adjacent channels

Question 10

What does SSID stand for?

Answer 10

service set identier

Question 11

What is the purpose of the SSID?

Answer 11

It gives a name to the wireless access point.

Question 12

How many characters long can an SSID be?

Answer 12

32

Question 13

Why are some SSIDs hidden?

Answer 13

Hiding it provides additional security.

Question 14

What Wi-Fi security methods are commonly used?

Answer 14

none, WEP, WPA, WPA2

Question 15

What does WEP stand for?

Answer 15

wired equivalent privacy

Question 16

What does WPA stand for?

Answer 16

wi-fi protected access

Question 17

Which is better: WEP or WPA?

Answer 17

wpa

Question 18

What is the legal maximum Wi-Fi signal in the USA?

Answer 18

100 milliwatts (mW)

Question 19

What does dBm stand for?

Answer 19

decibels milliwatt (decibels on a milliwatt scale)

Question 20

What is the dierence between dBm and dB?

Answer 20

dB is a relative measure. dBm is an absolute measure.

Question 21

What does SNR stand for?

Answer 21

signal noise ratio (signal to noise ratio)

Question 22

In what units is SNR measured?

Answer 22

decibels (dB)

Question 23

How much SNR do you need for a usable connection?

Answer 23

20 dB

Question 24

What is the typical range (in meters) for Wi-Fi signals?

Answer 24

100

Question 25

For typical Wi-Fi, how much signal (in dB) can be used up before the SNR is too low for useful communication?

Answer 25

50

Question 26

For typical Wi-Fi, how much signal (in dB) is lost per meter of open air?

Answer 26

0.5

Question 27

For typical Wi-Fi, how much signal (in dB) is lost per interior wall (plaster-board, wooden studs)?

Answer 27

5

Question 28

For typical Wi-Fi, how much signal (in dB) is lost per exterior wall (wood, brick, cement block, metal studs)?

Answer 28

10

Question 29

For typical Wi-Fi, how much signal (in dB) is lost per oor (thick ply- wood, support beams)?

Answer 29

15

Question 30

What typical indoor obstacles aect Wi-Fi signal strength?

Answer 30

Open air, interior walls, exterior walls, oors, furniture, cupboards, ap- pliances, people.

Question 31

What typical outdoor obstacles aect Wi-Fi signal strength?

Answer 31

Open air, people, trees, rain.

Question 32

What con | icts happen with 802.11b networks?

Answer 32

microwave ovens and cordless telephones