5

Is there any way for me to tell the maximum possible power of my wireless card from within Linux?

Or do I need to find the product number of the card, and search for specifications like that online?

  • You can find out the maximum broadcast power of the card with iw. The exact command evades me at the moment... – Lawrence Jul 17 '14 at 4:32
2
iwlist <interface> txpower

tells you that information, if device provides it.

Eg;

# iwlist eth0 txpower
eth0      8 available transmit-powers :
          5 dBm         (3 mW)
          7 dBm         (5 mW)
          9 dBm         (7 mW)
          11 dBm        (12 mW)
          13 dBm        (19 mW)
          15 dBm        (31 mW)
          17 dBm        (50 mW)
          19 dBm        (79 mW)
          Current Tx-Power=13 dBm       (19 mW)
  • It would be useful to provide sample output showing usage. – Patrick Jul 21 '14 at 6:14
  • Keep in mind that iwlist is being deprecated in favour of iw – Lawrence Jul 21 '14 at 6:24
  • @Lawrence Do you know the equivalent iw command that produces the same type of output? – IQAndreas Jul 22 '14 at 5:46
2

iw list will also tell you the allowed max power output by frequency. The number in brackets is the max power. I'm not aware of any other way of finding the absolute maximum of the device.

            Frequencies:
                    * 2412 MHz [1] (20.0 dBm)
                    * 2417 MHz [2] (20.0 dBm)
                    * 2422 MHz [3] (20.0 dBm)
                    * 2427 MHz [4] (20.0 dBm)
                    * 2432 MHz [5] (20.0 dBm)
                    * 2437 MHz [6] (20.0 dBm)
                    * 2442 MHz [7] (20.0 dBm)
                    * 2447 MHz [8] (20.0 dBm)
                    * 2452 MHz [9] (20.0 dBm)
                    * 2457 MHz [10] (20.0 dBm)
                    * 2462 MHz [11] (20.0 dBm)
                    * 2467 MHz [12] (20.0 dBm)
                    * 2472 MHz [13] (20.0 dBm)
                    * 2484 MHz [14] (disabled)
1

It is related to which country you live and have a look at WIFI power by country

Some software allow you to go higher than maximum allowed power but that is illegal.

  • It's exactly that "higher than maximum allowed" value I'm trying to find, I want to know what the card is capable of. In addition, some cards may have max power values lower than the maximum allowed by the country, so really, the "legal maximum" is irrelevant in this case. – IQAndreas Jul 17 '14 at 4:22
  • Generally the card will not let you go over the legal maximum. – Lawrence Jul 17 '14 at 4:25
  • Find technical spec document for your card, that would be your best shot. – Ask and Learn Jul 17 '14 at 4:33

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