CWNP - Certified Wireless Specialist new review solution
guide
Radio Frequency
Used to transmit and receive data on WLANs
Wavelength and Frequency Relationship
inversely related; One goes up and the other goes down.
Amplitude
The power or strength of a wave
Phase of a Wave
Used as a comparative attribute relating one wave to another
What does modulation use in WLANs?
Phase Shift Keys (PSK) and Amplitude Shift Keys (ASK)
What happens to RF energy when it passes through objects?
Many objects absorb some of the energy
How is RF transmission power referenced?
Watts (W) or Milliwatts (mW)
How is Received Signal Strength referenced?
dBm (Decibel/Milliwatt)
How do 802.11 devices achieve the data rate in the link?
Modulation and Coding Scheme (MCS)
What affects the achievable data rate?
Modulation, Coding, Channel Width, Spatial Streams
What Denotes the strength of an RF Wave or Signal?
Amplitude
What is decreased as the frequency of a wave increases?
Wavelength
What RF behavior is similar to light waves as seen in a mirror?
Reflection
What kind of modulation is not used in WLANs:
A) PSK
B) FSK
C) ASK
D) BPSK
FSK (Frequency Shift Key)
What is the name of the scheme that determines data rates in WLANs?
Modulation and Coding Scheme
What happens when RF energy is converted to heat when passing through some
materials?
Absorption
What modulation type uses only Phase Shift Keying?
A) BPSK
B) 16-QAM
C) 64-QAM
D) 256-QAM
, A. BPSK
In addition to modulation and coding, what other two primary factors impact the
data rate that is achievable in a WLAN link?
Channel Width and number of Spatial Streams
What comparative attribute relates an RF wave to another wave in the same
channel?
Phase
What metric is preferred by engineers and is used to represent received signal
strength?
dBm (Decibel/Milliwatt)
What do antennas do?
They radiate electromagnetic waves in the RF range in WLANs
Omnidirectional Antenna
Usually internal, radiates with 360 degree coverage uniformly.
Omnidirectional Antenna Placement
Usually indoors and placed in the center of the target coverage area
Semi-Directional Antennas
Radiate with a coverage window of about 50 - 180 degrees
Semi-Directional Antenna Placement
Usually placed in more high density areas and at the edge of the target area coverage
Highly-Directional Antennas
Best for very long distance links (bridge links), have a coverage radius less than 50
degrees
Highly-Directional Antenna Placement
Placed at both ends of a bi-directional link
Azimuth Chart
Shows the top-down view of an antennas horizontal propagation
Elevation Chart
Shows the side view of an antennas radiation pattern and indicates vertical propagation
Where are Internal AP antennas most common?
Indoor office deployments
Where are external AP antennas most common?
In situations where there is a need to provide specific coverage patterns in deployments
and for bridge links
What two fields make up an RF wave?
Electric and magnetic
Where are omnidirectional antennas typically placed within a target coverage
area?
At the center
What kind of antenna is usually placed at the edge of the target coverage area?
Patch and Panel Antennas (Semi-directional)
What unit is used to measure antenna gain?
dBi
Which chart shows the top-down view of an antennas propagation pattern?
Azimuth
When are external antennas used for indoor deployments?
guide
Radio Frequency
Used to transmit and receive data on WLANs
Wavelength and Frequency Relationship
inversely related; One goes up and the other goes down.
Amplitude
The power or strength of a wave
Phase of a Wave
Used as a comparative attribute relating one wave to another
What does modulation use in WLANs?
Phase Shift Keys (PSK) and Amplitude Shift Keys (ASK)
What happens to RF energy when it passes through objects?
Many objects absorb some of the energy
How is RF transmission power referenced?
Watts (W) or Milliwatts (mW)
How is Received Signal Strength referenced?
dBm (Decibel/Milliwatt)
How do 802.11 devices achieve the data rate in the link?
Modulation and Coding Scheme (MCS)
What affects the achievable data rate?
Modulation, Coding, Channel Width, Spatial Streams
What Denotes the strength of an RF Wave or Signal?
Amplitude
What is decreased as the frequency of a wave increases?
Wavelength
What RF behavior is similar to light waves as seen in a mirror?
Reflection
What kind of modulation is not used in WLANs:
A) PSK
B) FSK
C) ASK
D) BPSK
FSK (Frequency Shift Key)
What is the name of the scheme that determines data rates in WLANs?
Modulation and Coding Scheme
What happens when RF energy is converted to heat when passing through some
materials?
Absorption
What modulation type uses only Phase Shift Keying?
A) BPSK
B) 16-QAM
C) 64-QAM
D) 256-QAM
, A. BPSK
In addition to modulation and coding, what other two primary factors impact the
data rate that is achievable in a WLAN link?
Channel Width and number of Spatial Streams
What comparative attribute relates an RF wave to another wave in the same
channel?
Phase
What metric is preferred by engineers and is used to represent received signal
strength?
dBm (Decibel/Milliwatt)
What do antennas do?
They radiate electromagnetic waves in the RF range in WLANs
Omnidirectional Antenna
Usually internal, radiates with 360 degree coverage uniformly.
Omnidirectional Antenna Placement
Usually indoors and placed in the center of the target coverage area
Semi-Directional Antennas
Radiate with a coverage window of about 50 - 180 degrees
Semi-Directional Antenna Placement
Usually placed in more high density areas and at the edge of the target area coverage
Highly-Directional Antennas
Best for very long distance links (bridge links), have a coverage radius less than 50
degrees
Highly-Directional Antenna Placement
Placed at both ends of a bi-directional link
Azimuth Chart
Shows the top-down view of an antennas horizontal propagation
Elevation Chart
Shows the side view of an antennas radiation pattern and indicates vertical propagation
Where are Internal AP antennas most common?
Indoor office deployments
Where are external AP antennas most common?
In situations where there is a need to provide specific coverage patterns in deployments
and for bridge links
What two fields make up an RF wave?
Electric and magnetic
Where are omnidirectional antennas typically placed within a target coverage
area?
At the center
What kind of antenna is usually placed at the edge of the target coverage area?
Patch and Panel Antennas (Semi-directional)
What unit is used to measure antenna gain?
dBi
Which chart shows the top-down view of an antennas propagation pattern?
Azimuth
When are external antennas used for indoor deployments?
