CWDP: Certified Wireless Design Professional v303 — Question 17

What is the best method of gathering attenuation measurements from any building materials or objects?

Answer options

• A. After measuring the RSSI in free space 5 meters (16.5 feet) apart, put an AP 4 meters (13 feet) away from the wall or object on one side and your measuring device 0.67 meters (2 feet) away from the wall or object on the other side. Take measurement and compare the difference.
• B. Use the pre-built attenuation values in the predictive design tool.
• C. After measuring the RSSI in free space 1 meter (3 feet) apart, put an AP 0.32 meters (1 feet) away from the wall or object on the other side. Take measurements and compare the difference.
• D. Look on the Internet for attenuation values for each one of the materials that might attenuate the Wi-Fi signal using the material provider's websites.

Correct answer: C

Explanation

The correct answer, C, provides a specific method for accurately measuring attenuation by ensuring the AP is placed close to the object and comparing the RSSI in free space with the RSSI after the object is introduced. Option A uses a greater distance which may introduce additional variables and inaccuracies. Option B relies on pre-built values that may not be specific to the current scenario, and option D suggests an external search which may not yield precise measurements relevant to the specific materials in question.