wireless 1-5
Which 802.11 amendments provide for throughput of 1 Gbps or higher? (Choose all that apply.)
802.11ad 802.11ac
Which 802.11 radio technologies are most impacted by the destructive effects of multipath? (Choose all that apply.)
802.11g 802.11b 802.11a
Which 802.11 amendment defines wireless mesh networking mechanisms?
802.11s
WLAN vendors use RSSI thresholds to trigger which radio card behaviors? (Choose all that apply.)
Dynamic rate switching Roaming
The 802.11-2012 standard defines which two technologies for quality of service(QoS) in a WLAN?
EDCA Hybrid Coordination Function Controlled Channel Access
An ERP (802.11g) network mandates support for which two spread spectrum technologies?
ERP-DSSS/CCK ERP-OFDM
When determining the mounting height of a long-distance point-to-point antenna, which of the following needs to be considered? (Choose all that apply.)
Earth bulge RF line of sight Frequency Distance
The highest RF signal strength that is transmitted from an antenna is known as what?
Equivalent isotropically radiated power (EIRP)
What are some of the possible negative effects of an impendence mismatch? (Choose all that apply.)
Erratic signal strength Amplifier/transmitter failure Decreased signal amplitude
When implementing an 802.1X/EAP RSN network with a VoWiFi solution, what is needed to avoid latency issues during roaming?
Fast BSS Transition
In a normal wireless bridged network, the greatest loss of signal is caused by what component?
Free space path loss
Which wave properties can be modulated to encode data? (Choose all that apply.)
Frequency Amplitude
Which three properties are interrelated?
Frequency, wavelength, and the speed of light
To establish a 4-mile point-to-point bridge link in the 2.4 GHz ISM band, what factors should be taken under consideration? (Choose all that apply.)
Fresnel zone with 40 percent or less blockage Proper choice of semidirectional antennas
The 802.11b amendment defined which PHY?
HR-DSSS
A standard measurement of frequency is called what?
Hertz
Which of the following can cause refraction of an RF signal traveling through it? (Choose all that apply.)
Humidity Smog Change in air pressure Shift in the air temperature
The 802.11-2012 standard was created by which organization?
IEEE
What is the definition of the horizontal beamwidth of an antenna?
The distance between the two -3 dB power points on the horizontal axis, measured in degrees.
When a long-distance point-to-point link is installed, earth bulge should be considered beyond what distance?
7 miles
Which new technologies debuted in the 802.11ac-2013 amendment? (Choose all that apply.)
80 MHz channels MU-MIMO MU-MIMO
Which of the following are valid calculations when using the rule of 10s and 3s? (Choose all that apply.)
-For every 3 dB of gain (relative), double the absolute power (mW) -For every 10 dB of loss (relative), divide the absolute power (mW) by a factor of 10.
Which of the following statements are true about free space path loss? (Choose all that apply.)
-Path loss occurs at logarithmic rate. -RF signal will attenuate as they travel, despite the lack of attenuation caused by obstructions.
802.11 wireless bridge links are typically associated with which network architecture layer?
Distribution
Semidirectional antennas are often used for which of the following purposes? (Choose all that apply.)
-Providing short-distance point-to-point communications -Reducing reflections and the negative effects of multipath
Which of the following statements are true about amplification? (Choose all that apply.)
-RF amplifiers require an outside power source. -Antennas are passive gain amplifiers that focus the energy of a signal.
The radius of the second Fresnel zone is_____________. (Choose all that apply.)
-The area where the signal is out of phase with the point source -Larger than the first Fresnel zone
Which of the following are true for antenna diversity used by 802.11a/b/g access points?
-The transceiver samples both antennas and chooses the best received signal from one antenna. -Transceivers can transmit from only one of the antennas at a time.
Which of the following statements are true? (Choose all that apply.)
-When downfade occurs, the final received signal will never be stronger than the original transmitted signal. -When upfade occurs, the final received signal will never be stronger than the original transmitted signal.
The 802.11-2012 standard using an ERP-DSSS/CCK radio supports which data rates?
1, 2, 5.5, and 11 Mbps
When the multiple RF signals arrive at a receiver at the same time and are ___________ with the primary wave, the result can be ____________ of the primary signal.
180 degrees out of phase, cancellation
What is the frequency of an RF signal that cycles 2.4 million times per second?
2.4 MHz
23dBm is equal to how many mW?
200 mW
A wireless bridge is configured to transmit at 100mW. The antenna cable and connectors produce a 3 dB loss and are connected to a 16 dBi antenna. What is the EIRP?
2000 mW
A WLAN transmitter that emites a 100 mW signal is connected to a cable with a 3dB loss. If the cable is connected to an antenna with 7 dBi of gain, what is the EIRP at the antenna element?
250 mW
A wave is divided into degrees. How many degrees make up a complete wave?
360
2 dBd is equal to how many dBi?
4.14 dB
The Fresnel zone should not be blocked by more than what percentage to maintain a reliable communications link?
40 percent
A WLAN transmitter that emits a 400 mW signal is connected to a cable with a 9 dB loss. If the cable is connected to an antenna with 19 dBi of gain, what is the EIRP?
4W
An 802.11a radio card can transmit on the __________frequency and uses_________ spread spectrum technology.
5 GHz, OFDM
Maximum data rates of _______ are permitted using OFDM radios.
54 Mbps
To double the distance of a signal, the EIRP must be increased by how many dBs?
6 dB
What are the required data rates on an OFDM station?
6,12,and 24 Mbps
What is the primary reason that OFDM (802.11a) radios cannot communicate with ERP (80211g) radios?
802.11a operates a 5GHz, and 802.11g operates at 2.4 GHz.
Which keying method is most susceptible to interference from noise?
ASK
802.11 technology is typically deployed at which fundamental layer of network architecture?
Access
The signal between the transceiver and the antenna will be reduced by which of the following methods? (Choose all that apply.)
Adding an attenuator Using cheaper-quality cable Increasing the length of the cable
Amplifiers can be purchased with which of the following features? (Choose all that apply.)
All Fixed output Fixed gain Bidirectional amplification Unidirectional amplification
The height of power of a wave is known as what?
Amplitude
Which of the following refers to the polar chart of an antenna as viewed from above the antenna? (Choose all that apply.)
Azimuth chart Horizontal view H-plane
A robust security network (RSN) requires the use of which security mechanisms? (Choose all that apply.)
CCMP/AES 802.1X
What type of signal is required to carry data?
Carrier signal
Which types of devices were defined in the original 802.11 standard? (Choose all that apply.)
DSSS IR FHSS
As defined by the 802.11-2012 standard, which equipment is compatible? (Choose all that apply.)
DSSS and HR-DSSS ERP and HR-DSSS 802.11a and 802.11h
The IEEE 802.11-2012 standard defines communication mechanisms at which layers of the OSI model (Choose all that apply.)
Data-Link Physical
Which layers of the OSI model are referenced in the 802.11 standard? (Choose all that apply.)
Data-Link Physical
Select the units of comparison (relative). (Choose all that apply.)
Decibel Bel dBi dBd
What term is used to describe the time differential between a primary signal and a reflected signal arriving at a receiver?
Delay spread
When an RF signal bends around an object, this propagation behavior is known as what?
Diffraction
The size of the Fresnel zone is controlled by what factors? (Choose all that apply.)
Distance Frequency
While performing some research, Janie comes across a reference to a document titled RFC 3935. Which of the following organization's website would be best to further research this document?
IETF
The sum of all the components from the transmitter to the antenna, not including the antenna, is known as what? (Choose two.)
Intentional radiator IR
A point source that radiates RF signal equally in all directions is known as what?
Isotropic radiator
What are some objects or materials that are common causes of reflection? (Choose all that apply.)
Lake Asphalt road Metal
Which sublayer of the OSI model's Data-Link layer is used for communication between 802.11 radios?
MAC
Which of the following wireless communication parameters and usage are typically governed by a local regulatory authority? (Choose all at apply.)
Maximum transmit power Frequency Indoor/outdoor usage Bandwidth
Select the absolute units of power. (Choose all that apply.)
Milliwatt dBm Watt
Which organization is responsible for enforcing maximum transmit power rules in an unlicensed frequency band?
None of the Above
What are the security options available as defined in the original IEEE Std 802.11-1999 (R2003)? (Choose all that apply.)
Open System authentication WEP Shared Key authentication
What is the best example of a time domain tool that could be used by an RF engineer?
Oscilloscope
Which antennas are highly directional? (Choose all that apply.)
Parabolic dish Parabolic dish Grid
During a site survey of a point- to-point link between buildings at a manufacturing plant, the WLAN engineer determines that the noise floor is extremely high because of all the machinery that is operating in the buildings. The engineer is worried about low SNR and poor performance due to the high noise floor. What is a suggested best practice to deal with this scenario?
Plan for coverage cells with a 5 dB fade margin.
Which value should not be used to compare wireless network cards manufactured by different WLAN vendors?
RSSI
When calculating the link budget and system operating margin of a point-to-point outdoor WLAN bridge link, what factors should be taken into account? (Choose all that apply.)
Receive sensitivity Distance Transmit amplitude Frequency
Which RF behavior best describes a signal striking a medium and bending in a different direction?
Refraction
Which behavior can be described as an RF signal encountering a chain link fence, causing the signal to bounce into multiple directions?
Scatter
Which of these propagation behaviors can result in multipath? (Choose all that apply.)
Scattering Diffraction Reflection Refraction
The OSI model consists of how many layers?
Seven
While aligning a directional antenna, you notice that the signal drops as you turn the antenna away from the other antenna, but then it increases a little. This increase in signal is cause by what?
Side Lobe
Received signal strength indicator (RSSI) metrics are used by 802.11 radios to define which RF characteristics?
Signal strength
What is an example of a frequency domain tool that could be used by an RF engineer?
Spectrum analyze
A network administrator replaced some coaxial cabling used in an outdoor bridge deployment after water damaged the cabling. After replacing the cabling, the network administrator noticed that the EIRP increased drastically and is possibly violating the maximum EIRP power regulation mandate. What are the possible causes of the increased amplitude? (Choose all that apply.)
The administrator installed a higher-grade cable. The administrator installed a shorter cable.
dBi is a measure of what?
The signal increase caused by the antenna
What are the advantages of using unlicensed frequency bands for RF transmissions? (Choose all that apply.)
There is no additional financial cost Anyone can use the frequency band.
Which of the following are true about cables? (Choose all that apply.)
They cause impedance on the signal They add loss to the signal
The azimuth chart represents a view of antennas radiation pattern from which direction?
Top
Lightning arrestors will defend against which of the following?
Transient currents
What two technologies are used to prevent 802.11 radios from interfering with radar and satellite transmissions at 5 GHz?
Transmit power control Dynamic frequency selection
What RF components is responsible for generating the AC signal?
Transmitter
The 802.11h amendment(now part of the 802.11-2012 standard) introduced what two major challenges for 5 GHz radios?
U-NII-2 Extended Radar detection
What are some results of multipath interference? (Choose all that apply.)
Upfade Excessive retransmissions
The ratio between the maximum peak voltage and minimum voltage on a line is known as what?
VSWR
The Wi-Fi Alliance is responsible for which of the following certification programs?
WMM
What other Wi-Fi Alliance certifications required before a Wi-Fi radio can also be certified as Voice Enterprise compliant? (Choose all that apply.)
WMM-Admission Control WMM-Power Save WPA2-Enterprise
The Wi-Fi Alliance is responsible for which of the following certification programs? (Choose all that apply.)
WMM-PS Voice Personal
What terms best defines the linear distance traveled in one positive-to-negative-to-positive oscillation of an electromagnetic signal?
Wavelength
What organization ensures interoperability of WLAN products?
Wi-FI Alliance
Samantha received a gaming session as a gift. She would like to have it communicate with her sister Jennifer's gaming system so that they can play against each other. Which of the following technologies, if deployed in the two gaming systems, should provide for the easiest configuration of the two systems to communicate with each other?
Wi-Fi Direct
The 802.11u-2011 amendment is also known as what?
Wireless Interworking with External Networks (WIEN)
Using knowledge of RF characteristics and behaviors, which two options should a WLAN engineer be most concerned about during an indoor site survey? (Choose all that apply.)
Wood-lath plaster walls Brick walls
