List the three types of wave modulation:
What are the three ways a wave can be modulated?
How does a "Keying Method" relate to wave forms?
A keying method describes the type of modulation used. Amplitude Shift Keying - ASK
Frequency Shift Keying - FSK
Phase Shift Keying - PSK
Which keying method is used for WiFi?
PSK - Phase Shift Keying
What is the wavelength of the center 2.4ghz frequency?
4.82in - 12.24cm
What is the wavelength of the center 5ghz frequency?
2.04in - 5.19cm
What are the first and last channels and center frequencies used in the US for the 2.4Ghz band?
1 - 2412mhz 11 - 2462
What are the first and last channels and center frequencies used in the US for the 5 Ghz band?
36 - 5180
165 - 5825
What is the formula used to translate channels to frequency in the 5Ghz band?
(channel) x 5 + 5000
What are the center frequencies for channels 1 6 and 11?
How many mhz separate each channel in the 2.4ghz band?
How many mhz separate each 20 mhz wide channel in the 5ghz band?
What is the standard attenuation of sheetrock?
How many DB does 2.4ghz attenuate by in 1 meter?
How many DB does 5ghz attenuate by in 1 meter?
How many DB does signal attenuate when the distance between systems is doubled?
Which WiFi frames require an ACK?
Any unicast data frames.
Convert dbm to mw:
Convert dbm to mw:
What does the E plane show you on an azimuth chart?
elevation view - from the side
What does the H plane show you on an azimuth chart?
top down - overHead view
What are the three types of beamforming and how are they generally used?
Static beamforming - fixed anteanns - cell towers
Dynamic beamforming - adaptive antenna array used to switch power and signal patterns - Used by Ruckus
Transmit Beamforming - TxBF used in WiFi
List the two types of TxBF
implicit beamforming - uses channel sounding to guess optimied phasing
explicit beamforming - uses vmatrix received from client to determine correct phase shift
What is contained in the TxBF V matrix?
amplitude and phase per TX antenna per RX antenna per subtone
How much gain can be derived from TxBF?
How much can the first fresnel zone be obscured before causing an unrealiable link?
Does the beamwidth of the antenna have any bearing on the size of the fresnel zone?
Which fresnel zones are in-phase with the point source signal?
1 - 3 - 5
Which fresnel zones are out-of-phase with the point source signal?
2 - 4 - 6
At what distance must earth bulge be considered?
more than 7 miles or 11 kilometers
What antenna issue can cause a loss of 15-20db below expected received signal level?
What is the standard impedence for WiFi antenna systems?
What is the standard loss in db for each connection in an antenna system?
What is the standard db loss for 2.4 ghz in LMR 400 cable: