3 Replies Latest reply: Jan 28, 2009 6:55 PM by Tesserax
zsmith Level 1 Level 1 (0 points)
I was using Airport Utility in Advanced:Logs and Statistics:Wireless Clients
For a windows computer of mine I get
Signal: -1
Noise: -90
Rate :36 (sometimes 48,54)

For my iPod Touch I have
Signal: +61 (!?!)
Noise: 0
Rate: 27
The mac clients have signal in the range of -50 and noise in the -90 range.

These figure make little sense to me. What do they mean, or is there a bug in the AirPort (running 7.3.2)?

Airport extreme, version 7.3.2
  • Tesserax Level 8 Level 8 (49,860 points)
    Typically you will want the signal value to be less negative and the noise value to be more negative in utilities that utilize this type of measurements. Please note that these tools are not consistent. For example if you run AirRadar, iStumbler, and the AirPort Utility, you will most likely get different values for signal and noise so I would consider them as representing average values.

    More importantly you want to know the Signal-to-Noise Ratio (SNR). SNR is the signal level (in dBm) minus the noise level (in dBm). For example, a signal level of -53dBm measured near an access point and typical noise level of -90dBm yields a SNR of 37dB, a healthy value for wireless LANs.

    SNR Guideline
    o 40dB+ SNR = Excellent signal
    o 25dB to 40dB SNR = Very good signal
    o 15dB to 25dB SNR = Low signal
    o 10dB to 15dB SNR = Very low signal
    o 5dB to 10dB SNR = No signal

    The rate value is the average throughput (speed) value at any given instant in time and is measured in Mbps. So a value of 36 = 36 Mbps. The maximum bandwidth (best throughput) for a 802.11g wireless network is 54 Mbps. If you see this value fluctuating randomly, it may mean that there is some for of Wi-Fi interference in the local area that is affecting your wireless network.
  • zsmith Level 1 Level 1 (0 points)
    Dear Tesserax,

    I think you might have missed something. Not to be rude, but what you answered has nothing to do with what I asked. Look at the two examples I gave. A signal of +61 does not make sense! What is going on? Is there a bug in the Airport express software?
  • Tesserax Level 8 Level 8 (49,860 points)
    No problem. What I was trying to say is that the signal and noise values you are getting are at best only an approximate representation of their true values at any instant of time and any fluctuations (like the +61 value you got of the iPhone) may not be indicating a problem at all.

    However, to be more directly answer your question, the less negative the signal value and the more negative the noise level the better. I also addressed what the rate value mean ... and no, I don't see this as a bug in the AirPort Utility.