inconsistent data

  • Georgi Tonev

    Georgi Tonev - 2001-08-03

    I have a number of questions regarding the data returned by the aironet driver. First, I wonder how do we get the values for the ranges:

    airo.c, line #3716 we have:
    range.max_qual.qual = 10;
    range.max_qual.level = 100;
    range.max_qual.noise = 0;
    I am especially interested about the 'qual = 10' one.

    Second, why is it, that the further I go from the access point, the link quality gets better?! Using iwconfig, I have seen values of 22/10 (I was thinking that 10 is the max?!) When I am near the access point the link quality is 5/10 and just before going out of range it jumps to > 20/10?!
    This behavior is pretty consistent, so I won't have difficulty reproducing it and showing the dump. I have looked at the source of iwconfig and I don't think the problem is there!

    Finally, I noticed that altough the rate adjustment is set to auto,  it won't change to anything different than 11 Mb/s even as my laptop goes out of range of the antenae.

    I am not sure whether these are problems with the driver or not, but any help/explaination/comment will be appreciated!!!


    • Ken

      Ken - 2001-08-23

      From experience using these devices, I can tell you that signal quality seems to be a measurement of the lack of multipath signals reaching the antenna. That explains why the signal quality is poor near the AP - signal is bouncing everywhere and reaching the antenna. At great distances, only the primary signal, or a strong reflected signal will reach the antenna. You may notice that turning down the power on the card output will give you a better quality signal.

    • Georgi Tonev

      Georgi Tonev - 2001-08-23

      I can understand what you mean, but shouldn't this be the case for all wireless devices then. I don't know whether its the device or the combination of driver+device, but using Compaq card + orinoco driver does not have any such problems. Even an SMC card with orinoco driver works quite right (altough it has some other oddities:)
      In addition I read (somewhere) that the aironet card uses the same chipset as the above two (i.e. Prism II), but a different MAC controller (whatever that means).



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