An engineer measures the Wi-Fi coverage at a customer site The RSSI values are recorded as follows:
• Location A: -72 dBm
• Location B: -75 dBm
• Location C -65 dBm
• Location D -80 dBm
Which two statements does the engineer use to explain these values to the customer? (Choose two.)
The RF signal strength at location B is indeed weaker than at location A by a noticeable amount, as a 3 dB difference typically represents a power level reduction of 50%. Additionally, the RF signal strength at location C is 10 times stronger than location B due to a 10 dB difference, which translates to a power increase by a factor of 10. These explanations are based on the well-known dB rule of 3s and 10s in signal strength measurements.
The following matches options C & D perfectly: "For every 3 dB decrease, the power is cut in half. Similarly, every 10 dB increase in level is 10 times the power, and every 10 dB decrease in level results in 1/10 the power. This is sometimes referred to as the “rule of 3s and 10s.”" https://www.sciencedirect.com/topics/computer-science/signal-strength
C and D(is the closest correct) Because rule of 10 and 3s
A)-65dBm is enough for web browsing) - wrong https://community.cisco.com/t5/wireless-mobility-knowledge-base/snr-rssi-eirp-and-free-space-path-loss/ta-p/3128478#:~:text=The%20closer%20this%20value%20to,on%20power%20levels%20and%20design. "Typically voice networks require a -65dBm or better signal level while a data network needs -80dBm or better. Normal range in a network would be -45dBm to -87dBm depending on power levels and design" B) the closer the value to + side, the better the signal - wrong
C) -75dBm is 3dBm weaker than -72dBm, so this divides the coverage with 2 (50% less) D) imagine 2squaremeters equals -80dBm, then if each time the RSSI gets better 3dBm then the the x squaremeters get multiplied with 2. -80dBm = 2sqm -77dBm = 4sqm -74dBm = 8sqm -71dBm = 16sqm -68dBm = 32sqm -65dBm = 64sqm this means not only it is just 10 times stronger, but 32 times. D) Yet again, the closer the value to + side, the better the signal, not the other way around - wrong
oops - E) Yet again, the closer the value to + side, the better the signal, not the other way around - wrong
C and D 100%
Correct answer C for descarting wrong A,B,E, ...... then other correct answer D
C & D are correct
I'd go for A and B because read carefully - the mission is to explain it to a customer! A customer is non technical most probably and will see these equations as bullshit...
C is 100% correct A is subjective, but the all other choices are wrong, so A and C it is.
-65 should be enough for web browsing..