2018 - Avaliação Wireless - Curso Avançado e Radioenlace

Avaliação Wireless - Curso Avançado e Radio Enlace
Questões:
O que é um site survey ?

Quais as 3 coisas essenciais para fazer um site survey ?

O que é um hotspot e um deadspot ?

Quais os 2 sintomas de um roteador que não está aguentando a quantidade de clientes ?

Explique o ciclo de vida de uma rede ( desenho, implantação, validação, troubleshooting )

O fato do seu roteador ter 300 mbps significa que vc vai navegar nessa velocidade pela internet ?

Qual a latência máxima que uma rede deve ter ?

Use o Wifi Deadspot e analise a largura de banda em ( -38Dbm, -45Dbm, -54Dbm, -62Dbm, -70Dbm )

Explique a afirmação " Quanto + velocidade - robusto é o sinal, por isso o sinal do 802.11 G é mais robusto que o do 802.11 N"

Qual a latência aceitável do seu dispositivo até o seu AP ?

É verdade que celulares nunca ficam ociosos em redes Wifi ?

Qual o meio de autenticação que o WPA2 Enterprise usa ?

O que é Jittler ?

Explique a frase "Quanto maior o ganho da antena, mais concentrado é o sinal".

O que é EAP-TLS ?

Explique a frase "Celulares e pequenos dispositivos tem muito mais facilidade de receber do que enviar dados".

Descreva 5 pontos a se observar durante um site survey.

Quais as características de um site survey físico ?

Consiga uma planta baixa do campus e faça um site survey com as seguintes informações:
- Qual a faixa mais usada no local 5 ou 2.4 Ghz ?
- Qual a vazão de dados da rede/AP que vc está conectado ?
- Qual o canal mais usado no local e em volta ?
- Quais os SSIDs do AP ?
- Qual a área de cobertura em Metros quadrados ?

Quais as 3 abordagens de gerenciamento de redes wireless ?

Qual protocolo de gerenciamento garante o funcionamento e gerenciamento centralizado de dispositivos com diferentes fabricantes ?

Descreva pelo menos 5 funções de uma controladora.

Qual valor de uma controladora cisco, ubiquiti, hp, mikrotik ?

Uma interferência de mesmo canal que tenha quantos DBs não vai afetar o uso da rede ?

O que é channel bonding ?

Ao montar um enlace wireless qual o recomendado usar 20 ou 40 Mhz de largura de banda ? explique.

O que é interferência de rebarba causada por um AP usando a potencia máxima e com 40 Mhz ?

O Que é EIRP ?

O que é a portadora ?

O ar transmite sinais digitais ?

Porque precisamos de modulação ? 3 motivos.

O que é o padrão VSWR e quais os valores aceitaveis de energia refletida ou de eficiência ?

O que é Beamwidth e onde eu vejo essa informação ?

O que é a polarização da antena ?

O que é RSSI ?

Explique a relação entre modulação e taxa de transmissão e robustez do sinal.

Caso eu queira montar um sinal de 60 Mbps qual deve ser a taxa em mbps do meu enlace ?

O que é um Datasheet de um equipamento de TI ?

Explique o que é o raio de fresnel e qual a relação do tamanho do raio se eu usar 2.4 ou 5 Ghz.

Após descobrir o raio de fresnel qual deve ser a altura que tenho que colocar minha antena ?

O que é a atenuação do espaço livre ?

Mostre como criar um enlace usando o site airlink da ubiquiti.

Perguntas do Livro WCNA

Capitulo 7
1. An 802.11 wireless network name is known as which type of address? (Choose all
that apply.)
A. BSSID
B. MAC address
C. IP address
D. SSID
E. Extended service set identifier

2. Which two 802.11 topologies require the use of an access point?
A. WPAN
B. IBSS
C. Basic service set
D. Ad hoc
E. ESS
3. The 802.11 standard defines which medium to be used in a distribution system (DS)?
A. 802.3 Ethernet
B. 802.15
C. 802.5 token ring
D. Star-bus topology
E. None of the above

4. Which option is a wireless computer topology used for communication of computer devices
within close proximity of a person?
A. WWAN
B. Bluetooth
C. ZigBee
D. WPAN
E. WMAN

5. Which 802.11 service set may allow for client roaming?
A. ESS
B. Basic service set
C. IBSS
D. Spread spectrum service set

6. What factors might affect the size of a BSA coverage area of an access point? (Choose all
that apply.)
A. Antenna gain
B. CSMA/CA
C. Transmission power
D. Indoor/outdoor surroundings
E. Distribution system

7. What is the default configuration mode that allows an AP radio to operate in a basic
service set?
A. Scanner
B. Repeater
C. Root
D. Access
E. Nonroot

10. Which of these are included in the four topologies defined by the 802.11-2012 standard?
(Choose all that apply.)
A. DSSS
B. ESS
C. BSS
D. IBSS
E. FHSS

11. Which wireless topology provides citywide wireless coverage?
A. WMAN
B. WLAN
C. WPAN
D. WAN
E. WWAN

12. At which layer of the OSI model will a BSSID address be used?
A. Physical
B. Network
C. Session
D. Data-Link
E. Application

13. The basic service set identifier address can be found in which topologies? (Choose all
that apply.)
A. FHSS
B. IBSS
C. ESS
D. HR-DSSS
E. BSS

15. What method of dialog communications is used within an 802.11 WLAN?
A. Simplex communications
B. Half-duplex communications
C. Full-duplex communications
D. Dual-duplex communications

17. A network consisting of clients and two or more access points with the same SSID connected by an 802.3 Ethernet backbone is one example of which 802.11 topology? (Choose
all that apply.)
A. ESS
B. Basic service set
C. Extended service set
D. IBSS
E. Ethernet service set

18. What term best describes two access points communicating with each other wirelessly
while also allowing clients to communicate through the access points?
A. WDS
B. DS
C. DSS
D. DSSS
E. DSM

19. What components make up a distribution system? (Choose all that apply.)
A. HR-DSSS
B. Distribution system services
C. DSM
D. DSSS
E. Intrusion detection system

20. What type of wireless topology is defined by the 802.11 standard?
A. WAN
B. WLAN
C. WWAN
D. WMAN
E. WPAN


Capitulo 4

1. Which of the following refers to the polar chart of an antenna as viewed from above the
antenna? (Choose all that apply)
A. Horizontal view
B. Vertical view
C. H-plane
D. E-plane
E. Elevation chart
F. Azimuth chart

2. The azimuth chart represents a view of an antenna’s radiation pattern from which
direction?
A. Top
B. Side
C. Front
D. Both top and side

3. What is the definition of the horizontal beamwidth of an antenna?
A. The measurement of the angle of the main lobe as represented on the azimuth chart.
B. The distance between the two points on the horizontal axis where the signal decreases
by a third. This distance is measured in degrees.
C. The distance between the two –3 dB power points on the horizontal axis, measured
in degrees.
D. The distance between the peak power and the point where the signal decreases by half.
This distance is measured in degrees.

4. Which antennas are highly directional? (Choose all that apply.)
A. Omni
B. Patch
C. Panel
D. Parabolic dish
E. Grid
F. Sector

5. Semidirectional antennas are often used for which of the following purposes? (Choose all
that apply.)
A. Providing short-distance point-to-point communications
B. Providing long-distance point-to-point communications158 Chapter 4 ■ Radio Frequency Signal and Antenna Concepts
C. Providing unidirectional coverage from an access point to clients in an indoor
environment
D. Reducing reflections and the negative effects of multipath

6. The Fresnel zone should not be blocked by more than what percentage to maintain
a reliable communications link?
A. 20 percent
B. 40 percent
C. 50 percent
D. 60 percent

7. The size of the Fresnel zone is controlled by what factors? (Choose all that apply.)
A. Antenna beamwidth
B. RF line of sight
C. Distance
D. Frequency

8. When a long-distance point-to-point link is installed, earth bulge should be considered
beyond what distance?
A. 5 miles
B. 7 miles
C. 10 miles
D. 30 miles

10. Which of the following are true for antenna diversity used by 802.11a/b/g access points?
(Choose all that apply.)
A. The transceiver combines the signal from both antennas to provide better coverage.
B. Transceivers can transmit from both antennas at the same time.
C. The transceiver samples both antennas and chooses the best received signal from one
antenna.
D. Transceivers can transmit from only one of the antennas at a time.

12. The ratio between the maximum peak voltage and minimum voltage on a line is known as
what?
A. Signal flux
B. Return loss
C. VSWR
D. Signal incidents

13. What are some of the possible negative effects of an impendence mismatch? (Choose all that
apply.)
A. Voltage reflection
B. Blockage of the Fresnel zone
C. Erratic signal strength
D. Decreased signal amplitude
E. Amplifier/transmitter failure

14. 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.)
A. Frequency
B. Distance
C. Visual line of sight
D. Earth bulge
E. Antenna beamwidth
F. RF line of sight

19. The radius of the second Fresnel zone is . (Choose all that apply.)
A. The area where the signal is out of phase with the point source
B. The area where the signal is in phase with the point source
C. Smaller than the first Fresnel zone
D. Larger than the first Fresnel zone

20. 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?
A. Signal reflection
B. Frequency harmonic
C. Side band
D. Side lobe

Capitulo 2

1. What are some results of multipath interference? (Choose all that apply.)
A. Scattering delay
B. Upfade
C. Excessive retransmissions
D. Absorption

2. What term best defines the linear distance traveled in one positive-to-negative-to-positive
oscillation of an electromagnetic signal?
A. Crest
B. Frequency
C. Trough
D. Wavelength

3. Which of the following statements are true about amplification? (Choose all that apply.)
A. All antennas require an outside power source.
B. RF amplifiers require an outside power source.
C. Antennas are passive gain amplifiers that focus the energy of a signal.
D. RF amplifiers passively increase signal strength by focusing the AC current of the signal.

4. A standard measurement of frequency is called what?
A. Hertz
B. Milliwatt
C. Nanosecond
D. Decibel
E. K-factor

5. When an RF signal bends around an object, this propagation behavior is known as what?
A. Stratification
B. Refraction
C. Scattering
D. Diffraction
E. Attenuation

8. What is the frequency of an RF signal that cycles 2.4 million times per second?
A. 2.4 hertz
B. 2.4 MHz
C. 2.4 GHz
D. 2.4 kilohertz
E. 2.4 KHz

9. What is the best example of a time domain tool that could be used by an RF engineer?
A. Oscilloscope
B. Spectroscope
C. Spectrum analyzer
D. Refractivity gastroscope

14. Which of the following can cause refraction of an RF signal traveling through it? (Choose
all that apply.)
A. Shift in air temperature
B. Change in air pressure
C. Humidity
D. Smog
E. Wind
F. Lightning

15. Which of the following statements are true about free space path loss? (Choose all that
apply.)
A. RF signals will attenuate as they travel, despite the lack of attenuation caused by
obstructions.
B. Path loss occurs at a constant linear rate.
C. Attenuation is caused by obstructions.
D. Path loss occurs at a logarithmic rate

18. 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.)
A. Brick walls
B. Indoor temperature
C. Wood-lath plaster walls
D. Drywall

19. Which three properties are interrelated?
A. Frequency, wavelength, and the speed of light
B. Frequency, amplitude, and the speed of light
C. Frequency, phase, and amplitude
D. Amplitude, phase, and the speed of sound

20. Which RF behavior best describes a signal striking a medium and bending in a different
direction?
A. Refraction
B. Scattering
C. Diffusion
D. Diffraction
E. Microwave reflection

Capitulo 12

1. What are some recommended best practices when deploying a high-density WLAN?
(Choose all that apply.)
A. Deploying unidirectional MIMO patch antennas
B. Band steering of all clients to 5 GHz
C. Load balancing
D. Low AP transmit power
E. Layer 3 roaming

If the access points transmit on the same frequency channel in an MCA architecture, what
type of interference is caused by overlapping coverage cells?
A. Intersymbol interference
B. Adjacent channel interference
C. All-band interference
D. Narrowband interference
E. Co-channel interference

3. What variables might affect range in an 802.11 WLAN? (Choose all that apply.)
A. Transmission power
B. CSMA/CA
C. Encryption
D. Antenna gain
E. Physical environment

4. What can be done to fix the hidden node problem? (Choose all that apply.)
A. Increase the power on the access point.
B. Move the hidden node station.
C. Increase power on all client stations.
D. Remove the obstacle.
E. Decrease power on the hidden node station.

5. Layer 2 retransmissions occur when frames become corrupted. What are some of the causes
of layer 2 retries? (Choose all that apply.)
A. High SNR
B. Low SNR
C. Co-channel interference
D. RF interference
E. Adjacent channel interference

6. What scenarios might result in a hidden node problem? (Choose all that apply.)
A. Distributed antenna system
B. Coverage cells that are too large
C. Coverage cells that are too small
D. Physical obstruction
E. Co-channel interference

7. What are some of the negative effects of layer 2 retransmissions? (Choose all that apply.)
A. Decreased range
B. Excessive MAC sublayer overhead
C. Decreased latency
D. Increased latency
E. Jitter

8. Several users are complaining that their VoWiFi phones keep losing connectivity. The
WLAN administrator notices that the frame transmissions of the VoWiFi phones are corrupted when listened to with a protocol analyzer near the access point but are not corrupted
when listened to with the protocol analyzer near the VoWiFi phone. What is the most likely
cause of this problem?
A. RF interference
B. Multipath
C. Hidden node
D. Adjacent channel interference
E. Mismatched power settings

9. A single user is complaining that her VoWiFi phone has choppy audio. The WLAN administrator notices that the user’s MAC address has a retry rate of 25 percent when observed
with a protocol analyzer. However, all the other users have a retry rate of about 5 percent
when also observed with the protocol analyzer. What is the most likely cause of this
problem?
A. Near/far
B. Multipath
C. Co-channel interference
D. Hidden node
E. Low SNR

10. What type of interference is caused by overlapping coverage cells with overlapping
frequencies?
A. Intersymbol interference
B. Adjacent channel interference
C. All-band interference
D. Narrowband interference
E. Co-channel interference

12. Which of these weather conditions is a concern when deploying a long-distance point-topoint bridge link?
A. Wind
B. Rain
C. Fog
D. Changes in air temperature
E. All of the above

13. What variables might affect range in an 802.11 WLAN?
A. Wavelength
B. Free space path loss
C. Brick walls
D. Trees
E. All of the above

14. Given: Wi-Fi clients can roam seamlessly at layer 2 if all the APs are configured with the
same SSID and same security settings. However, if clients cross layer 3 boundaries, a layer
3 roaming solution will be needed. Which device functions as the home agent if a Mobile IP
solution has been implemented in an enterprise WLAN environment where no WLAN controller is deployed?
A. Wireless network management server (WNMS)
B. Access layer switch
C. Layer 3 switch
D. Access point on the original subnet
E. Access point on the new subnet

15. Which of the following can cause roaming problems? (Choose all that apply.)
A. Too little cell coverage overlap
B. Too much cell coverage overlap
C. Free space path loss
D. CSMA/CA
E. Hidden node

16. What are some problems that can occur when an access point is transmitting at full power?
(Choose all that apply.)
A. Hidden node
B. Co-channel interference
C. Mismatched power between the AP and the clients
D. Intersymbol interference

17. Why would a WLAN network administrator consider disabling the two lowest rates on an
802.11b/g/n access point? (Choose all that apply.)
A. Medium contention
B. Adjacent channel interference
C. Hidden node
D. Intersymbol interference
E. All of the above

18. Which type of interference is caused by destructive multipath?
A. Intersymbol interference
B. All-band interference
C. Narrowband interference
D. Wideband interference
E. Physical interference

19. In a multiple-channel architecture (MCA) design, what is the greatest number of nonoverlapping channels that can be deployed in the 2.4 GHz ISM band?
A. 3
B. 12
C. 11
D. 14
E. 4

20. What factors should be taken into consideration when designing a channel reuse plan for 5
GHz access points? (Choose all that apply.)
A. Regulatory channels permitted
B. Number of VLANs permitted
C. Encryption
D. DFS support for the clients
E. DFS support for the APs




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