Wireless, Chapter 9 - Design for Wireless Networking
A) Areas of RF interference C) Access point locations The main objectives of a wireless site survey are to determine areas of RF interference and RF coverage as well as locations of access points and other infrastructure devices. The applications used have more to do with capacity planning. Wiring closet locations and security implementations are factors that need to be taken into account but are not the main objectives.
A main objective of a WLAN site survey is to determine ___________ and ___________. (Choose the best two options.) A) Areas of RF interference B) Applications to be used C) Access point locations D) Wiring closet locations E) Security implementations
B) site survey lite
A process that includes performing some simple tests to determine the best RF channel to use as well as access point mounting, consideration of aesthetics, and connecting to the wired network for access to the Internet. A) site survey light B) site survey lite C) sight survey lite D) sight survey light
A) RF A spectrum analyzer can be used to view RF. Wireless packets, data rates, and association frames can be viewed with a protocol analyzer.
A spectrum analyzer can be used to view what? A) RF B) Wireless packets C) Data rates D) Association frames
C) Predictive A predictive modeling site survey is software-based and takes the attenuation values of the building and other materials into consideration. Active and passive are forms of manual site surveys and record actual information about the site.
A type of site survey that is software-based, requires minimum time on site, and takes into consideration the attenuation value of materials such as the type of walls and doors is___________. A) Active B) Passive C) Predictive D) Optional
wireless medical and other interfering devices
Different environments may have distinct types of challenges, what challenge or challenges could face health-care environments?
A) Channels 1 and 1 Co-channel interference is caused by two access points operating on the same RF channel. Access points operating on channels 1 and 2 may cause adjacent channel interference. Channels 1, 6, and 11 are non-overlapping channels and will not interfere with one another.
Co-channel interference is caused by access points on___________. A) Channels 1 and 1 B) Channels 1 and 2 C) Channels 1 and 6 D) Channels 1, 6, and 11
reflections and machine shop equipment
Different environments may have distinct types of challenges, what challenge or challenges could face industrial areas?
user and device density
Different environments may have distinct types of challenges, what challenge or challenges could face office cube farms?
high quantity of mobile devices
Different environments may have distinct types of challenges, what challenge or challenges could face educational environments?
walls and attenuation values
Different environments may have distinct types of challenges, what challenge or challenges could face general office spaces?
C) three to five
Many organizations plan on how many wireless devices per user? A) one to three B) two to four C) three to five D) four to six E) five to seven
B) Microwave ovens D) Cordless phones Non-Wi-Fi interference is interference by anything other than WLANs that operates in the same frequency range. AM radios and digital TV systems do not operate in the license-free bands. 802.11b interference is WLAN interference. Radar systems operate in the 5 GHz U-NII band.
Non-Wi-Fi interference for an 802.11g/n network can be caused by___________ and___________. (Choose two.) A) AM radios B) Microwave ovens C) 802.11b networks D) Cordless phones E) Radar systems F) Digital TV systems
A) Passive C) Active Manual site surveys can be either passive or active. Scanning is a method of locating WLANs. A spectrum analyzer will allow you to see the RF. A packet is information that carries computer data from one device to another.
The manual site survey consists of which possible methods? (Choose two.) A) Passive B) Scanning C) Active D) Spectrum E) Packet
post survey
The process of validating a wireless network.
-Size of the physical location -Intended use of the wireless network -Number of wireless mobile devices -Wireless client device capabilities -The environment -The performance expectations -Bring your own device (BYOD) acceptance -Building age and construction materials -Network infrastructure devices
The scope of the wireless site survey, capacity planning, and wireless network design is dependent on many factors, including the following:
passive active
The two types of manual site surveys are _________ and __________.
False, because it's not bandwidth-intensive
True or false, VoWLAN is a bandwidth-intensive application.
True
True or false, wireless networks are half-duplex, shared medium, and contention-based.
-Evaluate areas for RF coverage. -Locate and mitigate any sources of RF interference. -Determine wireless network capacity requirements. -Decide on locations for hardware infrastructure devices. -Identify the antenna types to be used. Evaluate the environmental conditions including RF propagation and attenuation.
What are the main objectives of a wireless site survey?
A) Spectrum analyzer B) Passive scanning utility A spectrum analyzer and a tool that passively scans for wireless networks, such as NetStumbler, can be used for a manual site survey. The other options' association and authentication can be viewed using a protocol analyzer and are not "standalone" tools.
What devices, tools, or programs can be used in a manual site survey? (Choose two.) A) Spectrum analyzer B) Passive scanning utility C) Predictive site analyzer D) Association analyzer E) Authentication analyzer
Voice over Wireless LAN
What does VoWLAN stand for?
spectrum analyzer
What tool is used to determine the areas of RF coverage and interference?
B) Active An active site survey requires the survey device to associate to an access point. A passive site survey monitors all access points in the area. A predictive modeling site survey does not involve associating to an access point. Associating to an access point is not a required part of manual testing.
When a device associates to an access point during a site survey, it is performing which type of survey? A) Predictive B) Active C) Passive D) Required
D) Yagi A semidirectional antenna such as a Yagi is a good choice for an application requiring coverage down a long hallway or corridor. Low- or high-gain omnidirectional antennas will provide 360-degree horizontal coverage. Parabolic dish antennas are typically used for outdoor, long range bridging.
When considering the use of antennas for WLAN deployment during a site survey, which antenna could be tested to verify proper coverage for a long hallway or corridor? A) High-gain omnidirectional B) Low-gain omnidirectional C) Parabolic dish D) Yagi
D) Document the areas on the floor plans or blueprints. Dead spots (areas that lack RF coverage) should be identified on floor plans or blueprints. This is part of standard documentation practices. Marking them with tape, taking a photograph, and showing the site manager in person are not the best ways to document dead spots.
When performing a manual site survey, choose the best way to identify areas that lack RF coverage. A) Mark them with tape so that they can be located at a later time. B) Use a camera to take a photograph and document it in the report. C) Show the site manager the areas that lack coverage. D) Document the areas on the floor plans or blueprints.
D) Manual verification should be performed, but it is not required. A verification of the predictive survey should be performed to verify that the survey meets the customer's requirements. Although not required, it should be considered.
When using a predictive modeling site survey approach, which of the following is true about manual verification? A) Manual verification never has to be performed. B) Manual verification is always required. C) Manual verification should be performed only at the customer's request. D) Manual verification should be performed, but it is not required.
A) Walk-through of location E) Spectrum analysis A walk-through of the location and spectrum analysis are both recommended guidelines when performing a manual site survey. Equipment purchase and client device configuration are additional factors to consider but are not part of the manual site survey. A predictive analysis is a software-based site survey solution that does not require manual testing.
Which guidelines are recommended when performing a manual site survey? (Choose two.) A) Walk-through of location B) Predictive analysis C). Equipment purchase D) Client device configuration E) Spectrum analysis
B) It takes less time than a passive survey to get accurate results. A predictive modeling site survey will take less time than a passive survey, because a passive survey requires a manual analysis. Onsite protocol analysis or scanning utility will determine areas of RF interference from WLANs. The predictive modeling survey does not help you choose manufacturers' equipment to be used in a deployment.
Which of the following is true of a predictive modeling survey? A) It takes more time than a passive survey to get accurate results. B) It takes less time than a passive survey to get accurate results. C) It finds areas of interference from neighboring WLANs. D) It helps you choose the manufacturer's equipment to be used for the WLAN.
C) -67 dBm Recommended received signal strength for voice applications in the 2.4 GHz ISM band at a data rate of 54 Mbps is about -67 dBm. A recommended SNR is more than 20 to 25 dB.
You are a network consultant hired to perform a manual site survey for a small office building. The wireless network to be installed will use data and voice. For backward compatibility, the customer needs to support 2.4 GHz equipment. To provide the highest QoS for the voice application, you recommend that the received signal strength be a minimum of___________ for a data rate of 54 mbps. A) -20 dBm B) -25 dBm C) -67 dBm D) -76 dBm
D) The channel plan should take all three floors into consideration. Because of RF propagation, site surveys are really three-dimensional. Therefore, in a three-story building all floors need to be taken into consideration. Omnidirectional antennas may be polarized either vertically or horizontally. Single-channel architectures use the same channel for multiple floors.
You are a network engineer tasked with performing a site survey for a multiple-channel architecture (MCA) system in a three-story building. Which characteristic must be considered while performing a site survey? A) All omnidirectional antennas should be vertically polarized. B) Multiple floors require the same channel. C) Each floor should be treated as an individual site survey. D) The channel plan should take all three floors into consideration.
B) OFDM OFDM networks operate in the 5 GHz U-NII band and would not affect an 802.11g/n network that operates in the 2.4 GHz ISM band. FHSS, DSSS, and ERP-OFDM all operate in the 2.4 GHz ISM band and could cause interference with an 802.11g network.
You are performing a protocol analysis in order to determine potential interference from other WLANs in the immediate area of the site survey. You discover several WLANs that can potentially cause interference with the proposed installation. Which technology in use would not have an impact on the 802.11g/n wireless network you are surveying for? A) FHSS B) OFDM C) DSSS D) ERP-OFDM E) PBCC
A) Signal strength B) SNR The signal strength and SNR are two important values to record during the manual site survey process. Signal loss and propagation loss have different effects, and packet retries are more of an issue with dynamic rate selection.
You are using a wireless client adapter with a site survey utility and a notebook computer to perform a manual site survey in a very small office building. Which values are important to record to verify proper RF coverage for the location? (Choose two.) A) Signal strength B) SNR C) Packet retries D) Signal loss E) Propagation loss
B) Configure the access points to operate in the 5 GHz band. Since new hardware will be purchased and backward compatibility is not required, you could recommend using wireless network hardware that works in the 5 GHz band. This will eliminate interference from the other tenants that are using the 2.4 GHz ISM band. Automatic channel selection, spectrum analysis, and predictive modeling site survey will not help, because surrounding access points already use the entire band.
You have been hired by a company to perform a WLAN site survey in a multitenant building. You discover numerous access points on channels 1, 6, and 11. To optimize the new deployment, what recommendation could you make to the customer? Assume that all new hardware will be purchased and backward compatibility is not required. A) Configure the access points to automatic channel selection for the 2.4 GHz ISM band. B) Configure the access points to operate in the 5 GHz band. C) Perform a spectrum analysis to find space in the 2.4 GHz band. D) Perform a predictive modeling site survey to determine which channels to use.
C) Accuracy Manual site surveys can be very accurate because actual readings are taken at the site using test access points and a wireless client. This can take quite some time to complete depending on the size of the location. Wireless hardware is required to perform the site survey, and access to the whole facility is required.
You have been hired by a company to perform a manual site survey. When explaining the difference between a manual and predictive modeling site survey, you let the customer know the advantages and disadvantages of each. A manual site survey has which advantage? A) Speed B) No hardware required C) Accuracy D) Facility access not required
D) Correct antenna selection In this situation, correct antenna selection is important to provide optimal coverage as well as proper aesthetics. In this example, a spectrum analysis or protocol analysis could be performed but is not required. Environmental conditions are typically not an issue in a small office deployment.
You need to perform a site survey for a small real estate office that currently has no wireless network. Which factors must be considered as part of the site survey? A) Spectrum analysis B) Packet analysis C) Environmental conditions D) Correct antenna selection
