Exam 350-401 topic 1 question 212 discussion

https://www.cisco.com/c/en/us/support/docs/wireless/5500-series-wireless-controllers/116057-site-survey-guidelines-wlan-00.html says BOTH answers: "Heat map that displays RF coverage for all ‘in-scope’ areas with coverage set at the target RSSI for cell edge with a signal legend." "The edge of the coverage for an AP is based on the signal strength and SNR measured as the client device moves away from the AP. " It also says stuff like "For voice deployments, it is recommended that the cell edge should be at -67 dBm with 20 percent overlap." and -67 dBm is more of an RSSI value than a SNR value so I'm going with C. RSSI but really..... its a roll of the dice isn't it?

Analyze and define the cell edge: This requires the use of AirMagnet Survey, although there are simple tools like Omnipeek or Wireshark that can be used to measure wireless traffic as a client roams from one AP to another. According to design best practices that revolve around the Cell Edge Design, a wireless handset should roam before the RSSI reaches -67 dBm. You can analyze signal strength and determine the approximate cell edge by measuring the signal strength in a beacon frame as you move from the center of one cell towards the edge of that cell. https://www.cisco.com/c/en/us/td/docs/wireless/technology/vowlan/troubleshooting/vowlan_troubleshoot/8_Site_Survey_RF_Design_Valid.html

Using ChatGPT: Survey and Planning: During a wireless site survey, the cell edge is determined by measuring the signal strength (RSSI) at various points around the AP.

it´s C The following is one of the elements that you should consider when performing a post assessment of the environment. Analyze and define the cell edge: This requires the use of AirMagnet Survey, although there are simple tools like Omnipeek or Wireshark that can be used to measure wireless traffic as a client roams from one AP to another. According to design best practices that revolve around the Cell Edge Design, a wireless handset should roam before the RSSI reaches -67 dBm. You can analyze signal strength and determine the approximate cell edge by measuring the signal strength in a beacon frame as you move from the center of one cell towards the edge of that cell. https://www.cisco.com/c/en/us/td/docs/wireless/technology/vowlan/troubleshooting/vowlan_troubleshoot/8_Site_Survey_RF_Design_Valid.pdf (page 2)

A, Google said that based on a Cisco site

In a post wireless survey, the signal-to-noise ratio (SNR) is used to depict the cell edge of the access points. SNR is a measure of the strength of the signal relative to the background noise level. At the cell edge, the SNR typically decreases, indicating a weaker signal relative to the noise level, which can affect the quality and reliability of the wireless connection.

RSSI mentions about RF signal (for my opinion)while AP cell edge is based on the signal strength and SNR on the client. So I go for SNR.

Considering the specific focus on depicting the cell edge of access points in a post wireless survey, the most directly relevant measurement is: A. SNR (Signal-to-Noise Ratio) While RSSI is also a valuable metric in assessing signal strength and coverage area, SNR specifically highlights the relationship between the signal strength and background noise, making it more indicative of the boundary where the signal quality diminishes significantly at the cell edge. Therefore, for depicting the cell edge of access points, SNR is the more directly applicable measurement.

I just re-checked. A is the correct answer - The edge of the coverage for an AP is based on the signal strength and SNR measured as the client device moves away from the AP.

Picturing the edge of the cells seems to be working based on RSSI. https://content.cisco.com/chapter.sjs?uri=/searchable/chapter/www.cisco.com/content/en/us/td/docs/wireless/technology/7920/site_survey/guide/7920ssg/survwipt.html.xml https://learningnetwork.cisco.com/s/question/0D53i00000KsodRCAR/how-to-determine-the-cell-edge

The Answer is not C here's why RSSI is Received Signal Strength, this is an acronim used and it is very useful to determine the location of a Device by using Location Services or it is also used to check the signal strength that a device actually has, this is not a Graph that SHOWS, the word "depict" means show/graph/drawing, and this can be done with Single Noise Ratio, the graph will show you what you need post Wireless Survey. I am going with A

RSSI is the answer

I agree that RSSI should be the answer

SNR needed to support performance requirements

It should be C

You have a next question 210 asking you for value of SNR So RSSI is measurement that you receive. But in order to calculate SNR you need to calculate also Floor noise right? And that is POST-analysis. So It should be SNR. But yes the question is heavily confusing because even in manual post survey is not properly defined if it is after measuring RSSI or SNR

Ans is C