Chapter 7 Answers to Review Questions
- The process of planning a wireless LAN to meet the stated design goals is known as a(n)
- network planning report (NPR)
- instrument review
- documentation report
- site survey
- Each of the following is a design goal of a site survey except
- implement a wired network infrastructure
- achieve the best possible performance from a WLAN
- determine the best location for access points
- develop wired networks optimized for a variety of applications
- Each of the following are times that a site survey should be performed except
- before installing a new wireless network
- before changing an existing wireless network
- after adding a wired user to the subnet
- when there are significant changes in personnel
- Access points used as wireless tools in site surveys should have the ability to adjust the
- output power
- antenna width
- spectrum allocation
- frame count
- A device that converts direct current from a battery to alternating current is a(n)
- DC-to-AC converter
- AC-to-DC converter
- Universal Power Adapter (UPA)
- Power Converter (PC)
- Asite survey analyzer is a measurement tool that is designed for conducting a wireless LAN site survey. Trueor False?
- A spectrum analyzer scans the entire radio frequency spectrum (2.4 GHz for 802.11b and 802.11g or 5 GHz for 802.11a) and provides a graphical display of the results. True or False?
- A network analyzer, sometimes called a packet snifferor protocol analyzer, is extensively used in the placement of the access point itself. True or False?
- There is no industry-standard form for site survey documentation. Trueor False?
- One important documentation tool is a digital camera. True or False?
- The most common business requirement is that a wireless network provides ______to its users. mobility
- If a(n) _____ antenna is being used then the AP should be placed in the center of the room or coverage area as much as possible. omnidirectional
- If a(n) _____ antenna is used then the AP should be positioned in one corner of the room. semi-directional
- The _____ patternis the area in which the signal can be received from the AP. coverage
- The _____ range is the farthest distance in which the signal can be received by the wireless device. transmission
- List three additional steps that should be taken when performing an outdoor site survey.
- If the survey is taken in the fall or winter after deciduous trees and bushes have lost their foliage, these should be noted because they could impact the RF signal after the leaves have grown back.
- Climatic conditions may need to be taken into account. In areas with large amounts of rainfall or fog, these elements should be considered in the placement of the AP or transmitter.
- If the antenna must be installed on a rooftop then there should be ready access to that location.
- Permits and zoning ordinances must also be carefully noted as non-RF information as well.
- What should be included in the narrative of a site survey report?
The narrative section should begin by stating the requirements from the customer regarding what they wanted from the site survey. This ensures that the material in the report has a clear focus on what problems are being addressed. The narrative section should also outline how the survey was conducted, know as the methodology. It is important to clearly outline in this section all of the steps that were taken in preparation as well as in conducting the actual survey itself. This makes it clear to the reader that the survey follows a recognized and methodical pattern, and shortcuts or questionable actions were not taken. The narrative section should also clearly reveal the results of the measurements.
- List five times that a site survey should be conducted.
- Before installing a new wireless network – It is important to evaluate the placement of the access points and antennas throughout the proposed site in order to meet the design goals.
- Before changing an existing wireless network - When modifying or extending an existing network structure, it is important to re-evaluate the placement of the access points and antennas.
- When there are significant changes in personnel – Adding several new employees to an office or moving employees from one area to another area may necessitate a new site survey.
- When there are changes in network needs - If employees are performing significantly different duties, such as downloading large files on a regular basis, then a new site survey should be performed.
- After making physical changes to a building - Remodeling may introduce new sources of interference, such as motors and metal structures within the coverage area of the access point.
- Describe two types of antennas that should be used on an AP when conducting a site survey.
A requirement for an access point used in a site survey is to have external antenna connectors. This allows for different configurations of antennas to be connected to the AP in order to perform different types of tests. An omnidirectional antenna radiates its signal out in all directions equally. If a high-gain dipole antenna is placed in the same position, however, the signal is pattern is different. It may be necessary to test omnidirectional and high-gain dipole antennas to determine the best signal pattern for the area. Semi-directional and highly-directional antennas are used for longer distances and are not commonly attached to a standard AP
- Describe the two types of spectrum analyzers.
A spectrum analyzer scans the entire radio frequency spectrum (2.4 GHz for 802.11b and 802.11g or 5 GHz for 802.11a) and provides a graphical display of the results. These results generally include a signal-to-noise ratio measured in dB illustrated as a graph. Another type of spectrum does not continuously scan the entire frequency spectrum but instead only looks at the signal-to-noise ratio on the frequency on which the device is transmitting. Although not as helpful as a spectrum analyzer, these single-frequency analyzers, nevertheless can provide useful information.