Deck 1

Question 1

802.11ac Wave 1

Answer 1

Channel Width 80 MHz
Spacial streams 3
no Mu-MIMO
Data Speed 1.3 Gbps

Question 2

802.11ac Wave 2

Answer 2

Channel Width 160 MHz
4 Spacial Streams
Has Mu-MIMO
Data Speed 2.6 Gbps

Question 3

802.11ac Wave 3

Answer 3

Channel Width 160 MHz
8 Spacial Streams
Has Mu-MIMO
Data Speed 4.5 Gbps

Question 4

Effective Isotropic Radiated Power (EIRP)

Answer 4

The actual power radiated from and antenna connected to a transmitter.

Question 5

dBm

Answer 5

The power ratio of decibels (dB) of measured power referenced to one Milliwatt (mW)

Question 6

Wavelength

Answer 6

The length of a single cycle of a wave, as distance measured between one peak or trough of a wave and the next.

Question 7

5 gHz frequency bands

Answer 7

5. 150 - 5.250
6. 250 - 5.350
7. 470 - 5.725
8. 725 - 5.825

Question 8

2.4 gHz frequency band

Answer 8

2.400 - 2.4835

14 channels

Question 9

Amplitude

Answer 9

Amount of energy of the wave; size of the wave

Question 10

Frequency

Answer 10

How often you see a wave over one second; cycles per second

Question 11

Co-channel interferrence

Answer 11

interference caused by two more transmitters using the same channel. signals overlapping with each other. Only a problem if two networks transmit at the same time. Common on 2.4 GHz on channels 1, 6, &11. To solve move one of them to a different channel. Can be used if 19 dBm difference between receiving deceiving devices because they can tell signals apart.

Question 12

neighboring channel interference

Answer 12

two different networks overlapping with each other and transmitting at the same time. can cause data corruption. common on 2.4 gHz. Acceptable if large difference in signal strength.

Question 13

Non 802.11 interference

Answer 13

other devices out there have the ability to use 2.4 gHz w/o using 802.11 standards. Example: microwave oven, cordless phones, baby monitors.

Question 14

Free Space path loss

Answer 14

As a signal expands in one direction, it will decrease in strength. Higher the frequency and greater the distance = more loss.

Question 15

Dynamic Rate Shifting (DRS)

Answer 15

The dynamic changing of modulation method by 802.11 devices based on current received signal strength (RSSI) and signal to noise ration (SNR) conditions. Device automatically adjusts modulation as you get farther away . To fix this you must increase transmitters in clusters

Question 16

Reflection

Answer 16

causes the wave to bounce off in a different direction. Use MIMO to solve. Receiver will receive multiple copies of the transmission and combines.

Question 17

Absorption

Answer 17

Concrete and other walls/materials absorb the signal

Question 18

Scattering

Answer 18

Caused by rough materials. when going through concrete walls for example the waves bounce of when coming out and go in different directions.

Question 19

Refraction

Answer 19

coming out in another direction, bending

Question 20

Diffraction

Answer 20

signals bend around

Question 21

Fresnel Zone

Answer 21

Problems with Point to Point; when objects get into the Fresnel zone, they can have an affect on the waves to arrive out of phase. Need to keep Fresnel zone clear. curvature of the earth can cause a problem about 2 miles away, or mountains as transmitters cannot see each other anymore.

Question 22

Hertz

Answer 22

Measure of frequency or cycles per second

Question 23

Band

Answer 23

a range of continuous frequencies.multiple frequencies that are continuous and can be grouped together for the same purpose, such as wireless Networks or Radio-stations.

Question 24

channels

Answer 24

Each band is divided into what’s called distinct channels. Each channel is usually given a specific channel-number and is also assigned to a specific Frequency within the Band

Question 25

Gain

Answer 25

the measure of how effectively an antenna can focus radio waves in a certain direction. greater the gain = more directional. 0 dBi means no direction. it is a sphere. emitting in all directions
4 dBi= omidirectional
12 dBi very directional s

Question 26

Polarization

Answer 26

The orientation of the electrical fields wave in comparison to the horizon.

Question 27

Basic Service Set (BSS)

Answer 27

Single access point operating in infrastructure mode, offering 802.11 services

Question 28

WLAN

Answer 28

wireless local area network (home, office)

Question 29

WMAN

Answer 29

Wireless-metropolitan area network

Question 30

WMAN

Answer 30

Wireless-metropolitan area network large business

Question 31

WWAN

Answer 31

wireless wide area network (country, global)

Question 32

Infrastructure Mode

Answer 32

mode used by an access point to offer wireless services to form wireless infrastructure

Question 33

Basic Service Area (BSA)

Answer 33

The bounded usable area of RF waves emitted from an access point. the outer range

Question 34

BSS Identifier (BSSID)

Answer 34

Unique identifier based on MAC address of an access point.

Question 35

Service Set Identifier (SSID)

Answer 35

The logical name of a wireless network defined as a text string Example: chosen name of network “Netgear62”

Question 36

Distribution system

Answer 36

The upstream wired connection from and access point to an existing network

Question 37

Extended Service Set (ESS)

Answer 37

Multiple access points operating in infrastructure mode, offering same SSID

Question 38

Independent Basic Service Set (IBSS)

Answer 38

Network created ad-hoc between two wireless clients, no connection to any existing wireless networks

Question 39

Repeater

Answer 39

Access point w/o a wired up-link and configured to repeat received RF waves. Used for extending WLAN to areas unreachable by wired links

Question 40

wireless mesh

Answer 40

repeaters repeaters repeaters