CWTS-11-Performing an RF Wireless LAN Site Survey

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

A, B. 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.

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

A, B. 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.

The manual site survey consists of which possible methods? (Choose two.) A. Passive B. Scanning C. Active D. Spectrum E. Packet

A, C. Manual site surveys can be either passive or active. Scanning is a method of locating wireless LANs. A spectrum analyzer will allow you to see the RF. A packet is information that carries computer data from one device to another.

A main objective of a wireless LAN 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

A, C. 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 implantations are factors that need to be taken into account but are not the main objectives.

Which guidelines are recommended when performing a manual site survey? (Choose two.) A. Walkthrough of location B. Predictive analysis C. Equipment purchase D. Client device configuration E. Spectrum analysis

A, E. A walkthrough 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.

A spectrum analyzer can be used to view what? A. Radio frequency B. Wireless packets C. Data rates D. Association frames

A. A spectrum analyzer can be used to view radio frequency. Wireless packets, data rates, and association frames can be viewed with a protocol analyzer.

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

A. Co-channel interference is caused by two access points operating on the same radio frequency channel. Access points operating on channels 1 and 2 may cause adjacent channel interference. Channels 1, 6, and 11 are nonoverlapping channels and will not interfere with one another.

Non-Wi-Fi interference for an 802.11g 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

B, D. Non-Wi-Fi interference is interference by anything other than wireless LANs 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 wireless LAN interference. Radar systems operate in the 5 GHz UNII band.

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 wireless LANs. D. It helps you choose the manufacturer's equipment to be used for the wireless LAN.

B. A predictive modeling site survey will take less time than a passive survey because a passive survey requires a manual analysis. On-site protocol analysis or scanning utility will determine areas of RF interference from wireless LANs. The predictive modeling survey does not help you choose manufacturers' equipment to be used in a deployment.

When a device associates to an access point during a site survey, it is performing what type of survey? A. Predictive B. Active C. Passive D. Required

B. 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.

You are performing a protocol analysis in order to determine potential interference from other wireless LANs in the immediate area of the site survey. You discover several wireless LANs that can potentially cause interference with the proposed installation. Which technology in use would not have an impact on the 802.11g wireless network you are surveying for? A. FHSS B. OFDM C. DSSS D. ERP-OFDM E. PBCC

B. OFDM networks operate in the 5 GHz UNII band and would not affect an 802.11g 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 have been hired by a company to perform a wireless LAN 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.

B. 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.

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

C. 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.

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

C. 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 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 quality of service 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

C. 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 signal-to-noise ratio is more than 20 to 25 dB.

When considering the use of antennas for wireless LAN 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. 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 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.

D. 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.

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.

D. Because of RF propagation, site surveys are really three-dimensional. Therefore in a three-story building all fl oors 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.

When performing a manual site survey, choose the best way to identify areas that lack RF coverage. A. Mark them with tape so 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 on the floor plans or blueprints.

D. 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.

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

D. 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.